fsi: occ: Add support for P10

The P10 OCC has a different SRAM address for the command and response
buffers. In addition, the SBE commands to access the SRAM have changed
format. Add versioning to the driver to handle these differences.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201120010315.190737-3-joel@jms.id.au
Signed-off-by: Guenter Roeck <linux@roeck-us.net>