Make audio switch option only in desktop platform

Author: Raltyro

source/funkin/ui/options/PreferencesMenu.hx

@@ -40,7 +40,9 @@ class PreferencesMenu extends Page<OptionsState.OptionsMenuPageName>
   var hudCamera:FlxCamera;
   var camFollow:FlxObject;
 
+  #if desktop
   var audioDeviceItem:EnumPreferenceItem<String>;
+  #end
 
   public function new()
   {
@@ -171,7 +173,9 @@ class PreferencesMenu extends Page<OptionsState.OptionsMenuPageName>
     createPrefItemCheckbox('Launch in Fullscreen', 'When enabled, the game automatically starts up in fullscreen mode.', function(value:Bool):Void {
       Preferences.autoFullscreen = value;
     }, Preferences.autoFullscreen);
+    #end
 
+    #if desktop
     audioDeviceItem = createPrefItemEnum('Audio Device', 'What audio device should the game playbacks sounds to.', generateAudioDeviceEnums(),
       (key:String, value:String) ->
     {
@@ -355,6 +359,7 @@ class PreferencesMenu extends Page<OptionsState.OptionsMenuPageName>
     return item;
   }
 
+  #if desktop
   function generateAudioDeviceEnums():Map<String, String>
   {
     var enums = ['Default' => 'Default'];
@@ -372,6 +377,7 @@ class PreferencesMenu extends Page<OptionsState.OptionsMenuPageName>
   {
     audioDeviceItem.changeEnums(generateAudioDeviceEnums(), Preferences.audioDevice);
   }
+  #end
 
   override function exit():Void
   {