we no longer use hbird_eval to stand for board using by
nuclei fpga development boards, we are now using nuclei_fpga_eval
to stand for it.

nowadays the fpga bitstream cpu freq is 16MHz, and uart tx/rx
both works at 115200bps, so we change the baudrate to 115200bps
Signed-off-by: Huaqi Fang <578567190@qq.com>

CCFLAGS is used by gcc and g++ compiler. So CFLAGS should be used for
gcc to avoid passing gcc flags to g++.

Although the program elf is uploaded successfully, the upload message is
still "Remote communication error.“, but actually upload works.

After fix, it will be "[Inferior 1 (Remote target) detached]"

By the way, I also checked latest nuclei-sdk 0.3.0 release with latest
rt-thread source code
Signed-off-by: Huaqi Fang <578567190@qq.com>

Signed-off-by: Huaqi Fang <578567190@qq.com>

Squashed commit of the following:

commit 32dd349ccff85cdcad81021b5185f8f7347786db
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Jun 11 16:08:08 2020 +0800

    bsp/nuclei: Add more documentation about how to use RT-Thread in RV-STAR
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit c9474c20a558e9d7934a3d72cc9bb17a98c20871
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Jun 11 14:06:42 2020 +0800

    bsp/nuclei: remove comments in rt_hw_*_drvinit
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 89b5caa2c3e55dc352b13f8e33229f03351b7049
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Jun 11 13:52:12 2020 +0800

    bsp/nuclei: Add a entry README.md for nuclei bsp
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit ae50d6e9bdc92ca4767c5ac7d0ded7252314a42e
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Jun 11 11:52:52 2020 +0800

    bsp/nuclei: update README.md cover more pinmux section
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 1a42d85dfe5bc7b009f057784249d54d0c82de0f
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Jun 11 08:52:06 2020 +0800

    bsp/nuclei: clean up unused code in drv_spi.c
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit b40edcdf59c96ef261f65a0c023a24ac78cabb39
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Jun 10 14:09:15 2020 +0800

    bsp/nuclei: Format the code comments for hw pinmux init
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit c8ae9fdfdb989bbff85d911fee3124abd9d145db
Author: Huaqi Fang <578567190@qq.com>
Date:   Mon Jun 8 17:12:43 2020 +0800

    bsp/nuclei: Add more drivers support for gd32vf103

    * More drivers are supported for rvstar board, see README.md
    * If user want to use these supported drivers, menuconfig is required
    * User also need to setup pinmux for its coresponding driver in
    board/board.c
Signed-off-by: Huaqi Fang <578567190@qq.com>
Signed-off-by: Huaqi Fang <578567190@qq.com>

* Nuclei RISC-V Processor support is added both RV32 and RV64
* Nuclei RVSTAR BSP is added, UART driver is added
* MSH works well in RVSTAR board

---------------------------

Squashed commit of the following:

commit b7368bc2ed725c42f9adc297d0e9cf3ed706a520
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 17 14:38:54 2020 +0800

    [BSP][Nuclei] Pretty source code
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 2c42a997f7b5d8aa53bdaf19ccb30596091a112d
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 16 15:51:03 2020 +0800

    [libcpu] Remove ARCH_NUCLEI in libcpu kconfig
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 915ad4c076ff3d7cebda896537605e7f7939b7af
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 16 15:50:00 2020 +0800

    [BSP][Nuclei] Remove ARCH_NUCLEI in bsp KConfig
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit fe43869c79675a25669447d57ea5d77385e07ca5
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 15 12:43:20 2020 +0800

    [BSP][NUCLEI] Simply application main.c

    Remove previous complicated application of gd32vf103_rvstar
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 8fd31727bc7ff51c83a3c47840cff1bfb100c0ba
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 15 12:38:04 2020 +0800

    [BSP][NUCLEI] Format application and board source code
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit b432308b20cdf24dfcc1398511d1d83bce6a9df2
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 15 11:58:28 2020 +0800

    [BSP][Nuclei] Format source code of drivers of gd32vf103
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 7366173d749d8a51ed8d48eca09007d27aee8ad8
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 15 11:54:02 2020 +0800

    [LIBCPU][NUCLEI] Optimize nuclei cpu portable code
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 8c2cd4745b7279a6721946d119441bbf7fd1a9c2
Author: Huaqi Fang <578567190@qq.com>
Date:   Tue Apr 14 15:45:42 2020 +0800

    nuclei: Update README.md
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit fa8a2f24ea5e4dbce714ffda16c1ce558e5b5ddb
Author: Huaqi Fang <578567190@qq.com>
Date:   Tue Apr 14 14:06:54 2020 +0800

    nuclei: Add gpio driver not tested
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 1be40bc50be43dfcdd105291bd24355498f9fef3
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 9 14:55:22 2020 +0800

    Nuclei: Update README.md
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 4c8beb204b7ee3e38c04e1f23a1f7e4ce48aa196
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 9 10:20:25 2020 +0800

    Nuclei: Change idle stack size from 256 to 396 bytes

    If changed to 396 bytes, then debug optimization level changed
    from O2 to O0, and the application can run successfully without
    stack overflow issue of tidle0 task
    warning: tidle0 stack is close to end of stack address.
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit da2bcf5c56ef32b611405a8e591ecd3f1e598b11
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 9 10:11:40 2020 +0800

    nuclei: Remove unused kconfig
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 0b932c677a7934d60e70da141744790aec202ef6
Author: Huaqi Fang <578567190@qq.com>
Date:   Thu Apr 9 09:32:22 2020 +0800

    nuclei: optimize drivers support
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 0431f6f01f6efab2900de552abede83639415431
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 8 19:28:02 2020 +0800

    tools: Update mkdist.py for nuclei bsp
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 0e1f502edfddff93a4a66c041be68560ef4828eb
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 8 18:46:58 2020 +0800

    nuclei: optimize rvstar support directory
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 1131f6e6483d8f2fbafe07f4e598fc8f802ee85d
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 8 18:37:24 2020 +0800

    nuclei: update kconfig
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit ad81c1d3bf9d80d2b561c94e903e7ce4ca2c68c6
Author: Huaqi Fang <578567190@qq.com>
Date:   Wed Apr 8 15:43:00 2020 +0800

    nuclei: Rename board name
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit d780138a1abf5da5097cc89e6a428ebeae06f284
Author: Huaqi Fang <578567190@qq.com>
Date:   Tue Apr 7 09:36:19 2020 +0800

    libcpu: Add Nuclei arch option in KConfig
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 60320d34b1d88315efe1b566fd6bc75c69851f06
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 3 16:51:01 2020 +0800

    nuclei: Update nuclei sdk of rt-thread support
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit a042b806efe0ea3bc9dba80ebc7696e5941ba35f
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 3 11:34:09 2020 +0800

    nuclei: modify application for not print anything
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 2a9603adcb584b29886a2b93ded2473f4e8bffb1
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 3 11:31:01 2020 +0800

    nuclei: Add .gitignore for nuclei bsp
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 34aaf6aebae75c3ee9d38cc17e6bdb826ed9e357
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 3 11:28:06 2020 +0800

    nuclei_sdk: update link script of rvstar to contain rt-thread needed sections

            /* section information for finsh shell */
            . = ALIGN(4);
            __fsymtab_start = .;
            KEEP(*(FSymTab))
            __fsymtab_end = .;

            . = ALIGN(4);
            __vsymtab_start = .;
            KEEP(*(VSymTab))
            __vsymtab_end = .;

            /* section information for initial. */
            . = ALIGN(4);
            __rt_init_start = .;
            KEEP(*(SORT(.rti_fn*)))
            __rt_init_end = .;

    The above code placed in rodata section
Signed-off-by: Huaqi Fang <578567190@qq.com>

commit 3451466e9d8da3c3c8a631be69f3c7a5e6220c21
Author: Huaqi Fang <578567190@qq.com>
Date:   Fri Apr 3 10:04:42 2020 +0800

    bsp: Add initial commit of nuclei rvstar board bsp
Signed-off-by: Huaqi Fang <578567190@qq.com>
Signed-off-by: Huaqi Fang <578567190@qq.com>