[CoreSpotlight] Adopt XAMCORE_4_0 changes in .NET. (#13942)

src/CoreSpotlight/CSCompat.cs

@@ -1,6 +1,6 @@
 // Compatibility stubs
 
-#if !XAMCORE_4_0 && IOS
+#if !NET && IOS
 
 using System;
 

src/corespotlight.cs

@@ -228,9 +228,7 @@ namespace CoreSpotlight {
 		bool MultiValued { [Bind ("isMultiValued")] get; }
 	}
 
-#if XAMCORE_4_0
-	[NoTV]
-#endif
+	[TV (9,0)] // Headers don't say, documentation says no, however everything works just fine in Xcode (and no warnings).
 	[iOS (9,0)]
 	[Mac (10,13)]
 	[EditorBrowsable (EditorBrowsableState.Advanced)]