Palmas device have control outputs like REGEN1, REGEN2, REGEN3,
SYSEN1 and SYSEN2. These control outputs can be used for controlling
external voltage switches to enabled/disable voltage outputs.

Add support of these control outputs through regulator framework.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>