hwmon: (pmbus/core) Notify regulator events

Notify regulator events in PMBus irq handler.

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Link: https://lore.kernel.org/r/20230328150335.90238-3-Naresh.Solanki@9elements.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>