I also found that you can simply hide the notification my taping and holding on it, then click disable notifications or something to that effect, which comes up. From that it will take you into the settings app where you can uncheck Show Notifications. This will hide any notification sent from the Google Play Services app including the update messages. Only downside to this is that if anything else uses this to show notifications, you won't get them.
So far, it only seems to affect the update messages which is good.