[spritekit] Enable missing API in watchOS (found by xtro)

src/spritekit.cs

@@ -1359,11 +1359,9 @@ namespace SpriteKit {
 		IntPtr InitWithURL (NSUrl url);
 #endif
 
-		[NoWatch]
 		[Export ("play")]
 		void Play ();
 
-		[NoWatch]
 		[Export ("pause")]
 		void Pause ();
 

tests/xtro-sharpie/watchOS-SpriteKit.todo

@@ -1,2 +0,0 @@
-!missing-selector! SKVideoNode::pause not bound
-!missing-selector! SKVideoNode::play not bound