Bug 1833855 [Linux] Build mozva (VA-API library wrapper) on Linux/Gtk r=alwu

Differential Revision: https://phabricator.services.mozilla.com/D178637

toolkit/toolkit.mozbuild

@@ -145,6 +145,7 @@ DIRS += [
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk':
     DIRS += [
+        '/media/mozva',
         '/toolkit/system/gnome',
     ]
 
@@ -187,6 +188,3 @@ if CONFIG['ENABLE_TESTS']:
 if CONFIG['FUZZING']:
     DIRS += ['/tools/fuzzing']
 
-if CONFIG['MOZ_WAYLAND']:
-    DIRS += ['/media/mozva']
-