[libata] Use ATA_UDMAx standard masks when filling driver's udma_mask info

The ATA_UDMAx masks are self-documenting, and far better than manually
writing in the hex mask.

Note that pata_it8213 mask differed from the comment.  Added a FIXME there.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_qstor.c b/drivers/ata/sata_qstor.c
index 6688ccb..9ab554d 100644
--- a/drivers/ata/sata_qstor.c
+++ b/drivers/ata/sata_qstor.c
@@ -176,7 +176,7 @@
 				  //FIXME ATA_FLAG_SRST |
 				  ATA_FLAG_MMIO | ATA_FLAG_PIO_POLLING,
 		.pio_mask	= 0x10, /* pio4 */
-		.udma_mask	= 0x7f, /* udma0-6 */
+		.udma_mask	= ATA_UDMA6,
 		.port_ops	= &qs_ata_ops,
 	},
 };