libata-sff: separate out BMDMA qc_issue

Separate out ata_bmdma_qc_issue() from ata_sff_qc_issue() such that
ata_sff_qc_issue() only deals with non-BMDMA SFF protocols (PIO and
nodata) while ata_bmdma_qc_issue() deals with the BMDMA protocols and
uses ata_sff_qc_issue() for non-DMA commands.  All the users are
updated accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/sata_mv.c

@@ -2358,7 +2358,7 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
 		if (IS_GEN_II(hpriv))
 			return mv_qc_issue_fis(qc);
 	}
-	return ata_sff_qc_issue(qc);
+	return ata_bmdma_qc_issue(qc);
 }
 
 static struct ata_queued_cmd *mv_get_active_qc(struct ata_port *ap)