hwmon: (pmbus/ltc2978) add support for LTC7132

Add support for LTC7132.
The relevant registers in the LTC7132 are identical to the LTC7880.
So it's just a matter of adding the chip id.

Signed-off-by: Felix Nieuwenhuizen <Felix.Nieuwenhuizen@etas.com>
Link: https://lore.kernel.org/r/20221027145135.31802-1-Felix.Nieuwenhuizen@etas.com


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