[SCSI] mpt2sas: Fix missing reference tag seed with Type 2 devices

Ensure that the initial reference tag is passed on to the HBA firmware
for DIF Type 2 devices.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Kashyap Desai <Kashyap.Desai@lsi.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>