scsi: ibmvfc: Add vhost fields and defaults for MQ enablement

Introduce several new vhost fields for managing MQ state of the adapter as
well as initial defaults for MQ enablement.

Link: https://lore.kernel.org/r/20210114203148.246656-2-tyreld@linux.ibm.com


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