scsi: hisi_sas: send three identify before phy up

When the v2 hw is attached with many disks through an expander, there
may be OOB reset resulting in a PHY going down after the speed is
negotiated (very low probability).

This issue is resolved by modifying the link control registers to send
three identify frames before the PHY is ready (according to 6.10.3.3.2
in SAS 3.0 spec) and close ready when the PHY is down.

Signed-off-by: NengLong Zhao <zhaonenglong@hisilicon.com>
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>