scsi: libsas: Refactor sas_ata_hard_reset()

Create function sas_ata_wait_after_reset() from sas_ata_hard_reset() as
some LLDDs may want to check for a remote ATA phy is up after reset.

Link: https://lore.kernel.org/r/1652354134-171343-2-git-send-email-john.garry@huawei.com


Tested-by: Yihang Li <liyihang6@hisilicon.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>