fix cross compiling on linux

Cross compiling with mingw on linux was failing because the compiler didn't write Resource.rc.

make[1]: *** No rule to make target '.eobjs/Linux/Windows/Run/Preprocessor_Environment_Editable/Resources.rc', needed by 'compile_game'.  Stop.

Resources.rc is needed on Win32 and linux cross compile and does nothing on normal linux builds. Tested on linux and linux mingw cross compile.