scsi: hisi_sas: disable dlvry queues once at reset for v2 hw

The Delivery queue enable register should only be written to once at
reset for v2 hw.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>