regulator: sm5703-regulator: Add regulators support for SM5703 MFD

Regulators block of SM5703 controls several voltage regulators which
are used to power various components. There are 3 LDO outputs ranging
from 1.5 to 3.3V, a buck regulator ranging from 1V to 3V, two fixed
voltage LDO regulators for powering the USB devices and one high-power
fixed voltage LDO line (actually two lines) meant to power high-power
USB devices.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
Link: https://lore.kernel.org/r/20220423085319.483524-6-markuss.broks@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>