scsi: qla2xxx: Use IOCB path to submit Control VP MBX command

Use IOCB patch to submit Control VP MBX command to reduce
bottle-neck for mbx interface.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>