Firemint has released an update to Real Racing HD for the iPad adding online multiplayer support via Apple’s Game Center in the forthcoming iOS 4.2 update. Real Racing HD will allow iPad players on iOS 4.2 to invite up to three friends to race in multiplayer games via Game Center either directly or via Game Center’s auto-matching service. The latest update also adds support for fast app switching and quick save and resume on iOS 4.2 and…