ahci: add another PCI ID for marvell

1b4b:91a3 seems to be another PCI ID for marvell ahci.  Add it.
Reported and tested in the following thread.

 http://thread.gmane.org/gmane.linux.kernel/1068354

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Alessandro Tagliapietra <tagliapietra.alessandro@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/ata/ahci.c

@@ -385,6 +385,8 @@ static const struct pci_device_id ahci_pci_tbl[] = {
 	  .driver_data = board_ahci_yes_fbs },			/* 88se9128 */
 	{ PCI_DEVICE(0x1b4b, 0x9125),
 	  .driver_data = board_ahci_yes_fbs },			/* 88se9125 */
+	{ PCI_DEVICE(0x1b4b, 0x91a3),
+	  .driver_data = board_ahci_yes_fbs },
 
 	/* Promise */
 	{ PCI_VDEVICE(PROMISE, 0x3f20), board_ahci },	/* PDC42819 */