regulator: Fixes for v3.13 A small set of driver fixes plus one larger core change which changes the way we check to see if we're using DT so that there aren't any races between deciding we're using DT and the regulator subsystem noticing. This makes the new support for substituting a dummy regulator and optional regulators work a lot better on DT systems since it ensures that we don't trigger probe deferral when we shouldn't which was causing bugs in clients.