Resolves#6077
If only `SDL_INIT_JOYSTICK` is used, `InputCommon::SDL::SDLState` later tries to initialize the game controller in a background thread, which on macOS causes a crash in `SDL_PumpEvents`. From [the SDL docs](https://wiki.libsdl.org/SDL_Init), `SDL_INIT_GAMECONTROLLER` implies `SDL_INIT_JOYSTICK`, so this should be a total superset of the previous behavior.
