Remove old YUV fixme

src/render/SDL_yuv_sw_c.h

@@ -66,11 +66,6 @@ int SDL_SW_CopyYUVToRGB(SDL_SW_YUVTexture * swdata, const SDL_Rect * srcrect,
                         int pitch);
 void SDL_SW_DestroyYUVTexture(SDL_SW_YUVTexture * swdata);
 
-/* FIXME: This breaks on various versions of GCC and should be rewritten using intrinsics */
-#if 0 /* (__GNUC__ > 2) && defined(__i386__) && __OPTIMIZE__ && SDL_ASSEMBLY_ROUTINES && !defined(__clang__) */
-#define USE_MMX_ASSEMBLY 1
-#endif
-
 #endif /* SDL_yuv_sw_c_h_ */
 
 /* vi: set ts=4 sw=4 expandtab: */