Update cpp_cmake.rst

update CMAKE_C_FLAGS when compile C file

Documentation/guides/cpp_cmake.rst

@@ -104,11 +104,12 @@ Creating the project
 
     set(EXE_NAME hellocpp)
 
+    SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${AC_HW_FLAGS} ${AC_DEFINES}")
     set(CMAKE_CXX_FLAGS     "${AC_HW_FLAGS} ${AC_DEFINES} ${AC_COMMON_FLAGS} ${AC_CXX_EXTRA_FLAGS}")
     if (PARAM_DEBUG)
         set(CMAKE_CXX_FLAGS     "${CMAKE_CXX_FLAGS} -g")
     endif()
-
+    
     set(CMAKE_SKIP_RPATH ON)
     set(CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_LINKER} ${AC_LINKER_FLAGS} -o ${EXE_NAME}.elf <OBJECTS> <LINK_LIBRARIES>")