regulator: Allow enabling GPIO regulator

Drivers need to be able to enable regulators that may be implemented as
GPIO regulators. Example: fsl_esdhc enables the vqmmc supply which is
commonly implemented as a GPIO regulator in order to switch between I/O
voltage levels.

Signed-off-by: Sven Schwermer <sven@svenschwermer.de>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
2 files changed