snic: add scsi host after determining max IOs.

scsi host is added after negotiating the max number of IOs with
Firmware.

Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>