[Bugfix][CPU] Remove C++ version in CPU OpBuilder (#3643)

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

op_builder/cpu/builder.py

@@ -28,7 +28,7 @@ class CPUOpBuilder(OpBuilder):
         return cpp_ext
 
     def cxx_args(self):
-        return ['-O3', '-std=c++14', '-g', '-Wno-reorder']
+        return ['-O3', '-g', '-Wno-reorder']
 
     def libraries_args(self):
         return []