Update libretro.h
Update libretro.h

Oggom/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX