hwmon: (pmbus/adm1275) add adm1281 support

Add support for adm1281 which is similar to adm1275 and other chips
of the series.

Signed-off-by: Jose Ramon San Buenaventura <jose.sanbuenaventura@analog.com>
Link: https://lore.kernel.org/r/20240425070948.25788-3-jose.sanbuenaventura@analog.com


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