chore: update LOS_BitmapFfz comment

函数LOS_BitmapFfz有2个参数，注释中只描述了一个参数，丢失了对参数numBits的描述，影响导出API文档。补充函数注释的@param部分。

close #I3U3SF
Signed-off-by: kenneth <459864689@qq.com>

kernel/include/los_bitmap.h

@@ -162,6 +162,7 @@ UINT16 LOS_HighBitGet(UINT32 bitmap);
  * <li>None</li>
  * </ul>
  * @param *bitmap   [IN] The bitmap pointer.
+ * @param numBits   [IN] The number of bits that is used to limit the bitmap range.
  *
  * @retval int The bit index of the first zero bit from LSB.
  * @par Dependency: