Re-add hack to use SDL/SDL.h ifndef _WIN32.

The correct convention is to use #include SDL.h in all cases but we have to
do this so Externals/SDL builds, which isn't in the best shape.

Source/Core/InputCommon/Src/ControllerInterface/SDL/SDL.h

@@ -5,14 +5,22 @@
 
 #include <list>
 
+#ifdef _WIN32
 	#include <SDL.h>
+#else
+	#include <SDL/SDL.h>
+#endif
 
 #if SDL_VERSION_ATLEAST(1, 3, 0)
 	#define USE_SDL_HAPTIC
 #endif
 
 #ifdef USE_SDL_HAPTIC
+	#ifdef _WIN32
 		#include <SDL_haptic.h>
+	#else
+		#include <SDL/SDL_haptic.h>
+	#endif
 	#define SDL_INIT_FLAGS	SDL_INIT_JOYSTICK | SDL_INIT_HAPTIC
 #else
 	#define SDL_INIT_FLAGS	SDL_INIT_JOYSTICK