Added missing import. Resolves #45

sdl.mod/source.bmx

@@ -374,6 +374,7 @@ Import "SDL/src/audio/wasapi/SDL_wasapi.c"
 Import "SDL/src/audio/wasapi/SDL_wasapi_win32.c"
 Import "SDL/src/audio/winmm/SDL_winmm.c"
 Import "SDL/src/core/windows/SDL_hid.c"
+Import "SDL/src/core/windows/SDL_immdevice.c"
 Import "SDL/src/core/windows/SDL_windows.c"
 Import "SDL/src/core/windows/SDL_xinput.c"
 Import "SDL/src/filesystem/windows/SDL_sysfilesystem.c"