[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_inic162x.c b/drivers/ata/sata_inic162x.c
index 8efc531..3de1834 100644
--- a/drivers/ata/sata_inic162x.c
+++ b/drivers/ata/sata_inic162x.c
@@ -594,7 +594,7 @@
 	.flags			= ATA_FLAG_SATA | ATA_FLAG_PIO_DMA,
 	.pio_mask		= 0x1f,	/* pio0-4 */
 	.mwdma_mask		= 0x07, /* mwdma0-2 */
-	.udma_mask		= 0x7f,	/* udma0-6 */
+	.udma_mask		= ATA_UDMA6,
 	.port_ops		= &inic_port_ops
 };