dt-bindings: hwmon: Add IBM OCC bindings

These bindings describe the POWER processor On Chip Controller accessed
from a service processor or baseboard management controller (BMC).

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220809200701.218059-2-eajames@linux.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>