pata_legacy: fix QDI6580DP support

Dual port QDI6580 has shared PIO timings for master/slave
devices so it needs to use custom ->qc_issue method.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_legacy.c

@@ -787,6 +787,7 @@ static struct ata_port_operations qdi6580_port_ops = {
 static struct ata_port_operations qdi6580dp_port_ops = {
 	.inherits	= &legacy_base_port_ops,
 	.set_piomode	= qdi6580dp_set_piomode,
+	.qc_issue	= qdi_qc_issue,
 	.sff_data_xfer	= vlb32_data_xfer,
 };