Don't use CoreMotion on tvOS

include/SDL_config_iphoneos.h

@@ -139,8 +139,12 @@
 #define SDL_JOYSTICK_MFI 1
 #define SDL_JOYSTICK_HIDAPI 1
 
+#ifdef __IPHONEOS__
 /* Enable the CoreMotion sensor driver */
 #define SDL_SENSOR_COREMOTION   1
+#else
+#define SDL_SENSOR_DUMMY    1
+#endif
 
 /* Enable Unix style SO loading */
 #define SDL_LOADSO_DLOPEN 1