add threaded input option

https://github.com/unknownbrackets/ppsspp/commit/b641ced7e0b5dc79cfe83aaed19df05bc6d84837
https://github.com/hrydgard/ppsspp/issues/3338

Someone needs to implement the exception for linux/unix, otherwise it will crash on unload if using this option.
Otherwise it should work just the same