[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_uli.c b/drivers/ata/sata_uli.c
index 6815de7..aca7181 100644
--- a/drivers/ata/sata_uli.c
+++ b/drivers/ata/sata_uli.c
@@ -129,7 +129,7 @@
 	.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 			  ATA_FLAG_IGN_SIMPLEX,
 	.pio_mask       = 0x1f,		/* pio0-4 */
-	.udma_mask      = 0x7f,		/* udma0-6 */
+	.udma_mask      = ATA_UDMA6,
 	.port_ops       = &uli_ops,
 };