Add a hover sample type for SongSelect buttons

osu.Game/Graphics/UserInterface/HoverSounds.cs

@@ -53,6 +53,9 @@ namespace osu.Game.Graphics.UserInterface
         Soft,
 
         [Description("-toolbar")]
-        Toolbar
+        Toolbar,
+
+        [Description("-songselect")]
+        SongSelect
     }
 }

osu.Game/Screens/Select/FooterButton.cs

@@ -14,6 +14,7 @@ using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.Containers;
 using osu.Game.Input.Bindings;
 using osu.Framework.Input.Bindings;
+using osu.Game.Graphics.UserInterface;
 
 namespace osu.Game.Screens.Select
 {
@@ -65,6 +66,7 @@ namespace osu.Game.Screens.Select
         private readonly Box light;
 
         public FooterButton()
+            : base(HoverSampleSet.SongSelect)
         {
             AutoSizeAxes = Axes.Both;
             Shear = SHEAR;