This patch adds support for a programmable enable pin. It can be used in
situations where the ANA-vcc is not configurable (dummy-regulator), or
just to have a more fine control of the power saving.

The use of the enable pin is optional.
Signed-off-by: NRicardo Ribalda Delgado <ribalda@kernel.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>