Fixed invalid use of CC_TARGET_PLATFORM in the CCClippingNode

I modified CC_PLATFORM_WINDOWS to CC_PLATFORM_WIN32.

--
In the CCPlatformConfig.h,
the definitions are..

// win32
#if defined(WIN32) && defined(_WINDOWS)
#undef
CC_TARGET_PLATFORM
#define CC_TARGET_PLATFORM
CC_PLATFORM_WIN32
#endif
Merge pull request #8125 from cpascal/fix_invalid_windows_definition

Fixed invalid use of CC_TARGET_PLATFORM in the CCClippingNode