For idle loops, don't explicitly call CoreTiming::Advance.

This is more consistent with the way Dolphin behaves with idle skipping off.

Source/Core/Core/PowerPC/PowerPC.cpp

@@ -510,15 +510,7 @@ void CheckBreakPoints()
 	}
 }
 
-void OnIdle(u32 _uThreadAddr)
-{
-	u32 nextThread = Memory::Read_U32(_uThreadAddr);
-	//do idle skipping
-	if (nextThread == 0)
-		CoreTiming::Idle();
-}
-
-void OnIdleIL()
+void OnIdle()
 {
 	CoreTiming::Idle();
 }