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/pata_radisys.c

@@ -179,7 +179,7 @@ static unsigned int radisys_qc_issue(struct ata_queued_cmd *qc)
 				radisys_set_piomode(ap, adev);
 		}
 	}
-	return ata_sff_qc_issue(qc);
+	return ata_bmdma_qc_issue(qc);
 }