hwmon: (pmbus) Increase maximum number of phases per page

Increase maximum number of phases from 8 to 10 to support multi-phase
devices allowing up to 10 phases.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20210511055619.118104-2-vadimp@nvidia.com


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