regulator: bd71837: add property for omitting ON/OFF control

regulator: bd71837: add property for omitting ON/OFF control

The BD718(37/47/50) regulator enable states can be controlled either by SW
or by PMIC internal state machine.

On some systems mixture of SW and HW state machine controlled regulators is
needed.

Specifically, some SoCs signal SUSPEND state change to PMIC via
STBY_REQ line. Now there are setups that expect certain regulators then to
be disabled (by PMIC state machine) while other regulators should stay
enabled (regardless of HW state => SW control required).

Add a new device-tree property "rohm,no-regulator-enable-control" which can
be used to leave regulator(s) under HW state machine control.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/9ff1104579093e7977944be769d625b9e33bc663.1599029334.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>