Allow reading background events for MFi controllers

src/joystick/iphoneos/SDL_mfijoystick.m

@@ -69,6 +69,9 @@ static NSString *GCInputXboxShareButton = @"Button Share";
 #if !((__IPHONE_OS_VERSION_MAX_ALLOWED >= 130000) || (__APPLETV_OS_VERSION_MAX_ALLOWED >= 130000) || (__MAC_OS_VERSION_MAX_ALLOWED >= 1500000))
 @property(nonatomic, readonly) NSString *productCategory;
 #endif
+#if !((__IPHONE_OS_VERSION_MAX_ALLOWED >= 140500) || (__APPLETV_OS_VERSION_MAX_ALLOWED >= 140500) || (__MAC_OS_X_VERSION_MAX_ALLOWED >= 110300))
+@property(class, nonatomic, readwrite) BOOL shouldMonitorBackgroundEvents;
+#endif
 @end
 @interface GCExtendedGamepad (SDL)
 #if !((__IPHONE_OS_VERSION_MAX_ALLOWED >= 121000) || (__APPLETV_OS_VERSION_MAX_ALLOWED >= 121000) || (__MAC_OS_VERSION_MAX_ALLOWED >= 1401000))
@@ -572,6 +575,10 @@ IOS_JoystickInit(void)
             return 0;
         }
 
+        if (@available(macOS 11.3, iOS 14.5, tvOS 14.5, *)) {
+            GCController.shouldMonitorBackgroundEvents = YES;
+        }
+
         /* For whatever reason, this always returns an empty array on
          macOS 11.0.1 */
         for (GCController *controller in [GCController controllers]) {