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>
          .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 */