This provides structure for the regulator device hierarchy and a
driver for GPIO-controlled regulators along with its binding.
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
This PR follows Linux in defining devicetree content for generic
voltage and current regulators, and an initial driver API for
controlling them.
A regulator itself may depend on a power source, so it needs to
support the properties that enable that power source.
Signed-off-by: Peter A. Bigot <pab@pabigot.com>