Fixed a build error in SDL_platform.h when using Code Blocks and MinGW

winapifamily.h, a header file specific to Microsoft's Windows 8 SDK, wasn't
getting found, which was leading to a build error.

include/SDL_platform.h

@@ -114,10 +114,10 @@
 #define __SOLARIS__ 1
 #endif
 
-#if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
+#if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
 /* Try to find out if we're compiling for WinRT or non-WinRT */
 /* If _USING_V110_SDK71_ is defined it means we are using the v110_xp or v120_xp toolset. */
-#if defined(__MINGW32__) || (defined(_MSC_VER) && (_MSC_VER >= 1700) && !_USING_V110_SDK71_)	/* _MSC_VER==1700 for MSVC 2012 */
+#if (defined(_MSC_VER) && (_MSC_VER >= 1700) && !_USING_V110_SDK71_)	/* _MSC_VER==1700 for MSVC 2012 */
 #include <winapifamily.h>
 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
 #undef __WINDOWS__