macosx: proper menu validation for all menus

Especially this fixes validation for audio and playback menus.
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>
(cherry picked from commit a6fcfb77)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/macosx/controls.m

@@ -37,6 +37,7 @@
 #import "open.h"
 #import "controls.h"
 #import "playlist.h"
+#import "MainMenu.h"
 #import "CoreInteraction.h"
 #import <vlc_keys.h>
 
@@ -403,3 +404,12 @@
 }
 
 @end
+
+@implementation VLCControls (NSMenuValidation)
+
+- (BOOL)validateMenuItem:(NSMenuItem *)o_mi
+{
+    return [[VLCMainMenu sharedInstance] validateMenuItem:o_mi];
+}
+
+@end