scsi: ibmvfc: Add protocol field to ibmvfc_channels

There are cases in the generic code where protocol specific configuration
or actions may need to be taken. Add a protocol field to struct
ibmvfc_channels and initial IBMVFC_PROTO_[SCSI/NVME] definitions.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-10-tyreld@linux.ibm.com


Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>