Add regulator driver for Spreadtrum SC2731 device.
It has 17 general purpose LDOs, BUCKs generator and
digital output to control regulators.
Signed-off-by: NErick Chen <erick.chen@spreadtrum.com>
Reviewed-by: NBaolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: NMark Brown <broonie@kernel.org>