libata: implement ATA_FLAG_IGN_SIMPLEX and use it in sata_uli

Some uli controllers have stuck SIMPLEX bit which can't be cleared
with ata_pci_clear_simplex(), but the controller is capable of doing
DMAs on both channels simultaneously.  Implement ATA_FLAG_IGN_SIMPLEX
which makes libata ignore the simplex bit and use it in sata_uli.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_uli.c b/drivers/ata/sata_uli.c
index 5c603ca..a43aec6 100644
--- a/drivers/ata/sata_uli.c
+++ b/drivers/ata/sata_uli.c
@@ -128,7 +128,8 @@
 
 static struct ata_port_info uli_port_info = {
 	.sht            = &uli_sht,
-	.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY,
+	.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
+			  ATA_FLAG_IGN_SIMPLEX,
 	.pio_mask       = 0x1f,		/* pio0-4 */
 	.udma_mask      = 0x7f,		/* udma0-6 */
 	.port_ops       = &uli_ops,