Added additional check for HAVE_D3D12_H and missing SDL_VIDEO_RENDER_D3D12 in SDL_config.h.cmake

CMakeLists.txt

@@ -1594,6 +1594,8 @@ elseif(WINDOWS)
     check_c_source_compiles("
       #include <winsdkver.h>
       #include <sdkddkver.h>
+      #include <d3d12.h>
+      ID3D12Device5 *device;
       #if WDK_NTDDI_VERSION > 0x0A000008
       int main(int argc, char **argv) { return 0; }
       #endif" HAVE_D3D12_H)