hwmon: (occ) Add soft minimum power cap attribute

Export the power caps data for the soft minimum power cap through hwmon.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220215151022.7498-5-eajames@linux.ibm.com


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