Build config flags are either defined or undefined, never 0

This is for consistency with CMake build configuration

Also added SDL_VIDEO_RENDER_GPU to the non-CMake build configurations

src/filesystem/gdk/SDL_sysfilesystem.cpp

@@ -141,5 +141,3 @@ char *SDL_SYS_GetUserFolder(SDL_Folder folder)
     SDL_Unsupported();
     return NULL;
 }
-
-// vi: set ts=4 sw=4 expandtab: