hwmon: (pmbus/lm25066) Add regulator support

hwmon: (pmbus/lm25066) Add regulator support

While these chips aren't strictly advertised as voltage regulators per
se, they (aside from the lm25056) support the PMBus OPERATION command
to enable and disable their outputs and have status bits for reporting
various warnings and faults, and can hence usefully support all the
pmbus_regulator_ops operations.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20220219000742.20126-1-zev@bewilderbeest.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>