Move regulator earlier in link sequence.

The regulator core currently initializes as a core_initcall() to be
available early ... but then it links way late, throwing away that
benefit, so regulators available at e.g. subsys_initcall() are not
available to subsystems which need to use them.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>