fsi: occ: Don't accept response from un-initialized OCC

If the OCC is not initialized and responds as such, the driver
should continue waiting for a valid response until the timeout
expires.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Fixes: 7ed98ddd ("fsi: Add On-Chip Controller (OCC) driver")
Link: https://lore.kernel.org/r/20210209171235.20624-2-eajames@linux.ibm.com


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