scsi: libsas: Add sas_execute_ata_cmd()

Add a function to execute an ATA command using the TMF code, and use in the
hisi_sas driver. That driver needs to be able to issue the command on a
specific phy, so add an interface for that.

With that, hisi_sas_exec_internal_tmf_task() may be deleted.

Link: https://lore.kernel.org/r/1645534259-27068-19-git-send-email-john.garry@huawei.com


Tested-by: Yihang Li <liyihang6@hisilicon.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>