Nope. Regulator is only good for 800mA, and from 12V source it will get Real hot with that much current and likely go into thermal shutdown.
Better to split the 12V supplly line and add a 2nd regulator.
Even better, use a switching regulator to bring the 12V down to 5V for the phone & servo and the other part, get away from just blowing all the 12V power as heat.
Examples: