Update SDL2 to the latest commit (85bbf8e)

libs/SDL2/include/SDL_touch.h

@@ -95,6 +95,14 @@ extern DECLSPEC int SDLCALL SDL_GetNumTouchDevices(void);
  */
 extern DECLSPEC SDL_TouchID SDLCALL SDL_GetTouchDevice(int index);
 
+/**
+ * Get the touch device name as reported from the driver or NULL if the index
+ * is invalid.
+ *
+ * \since This function is available since SDL 2.0.22.
+ */
+extern DECLSPEC const char* SDLCALL SDL_GetTouchName(int index);
+
 /**
  * Get the type of the given touch device.
  *