vxge: Titan1A detection

Detect if the adapter is Titan or Titan1A, and tune the driver for this
hardware.  Also, remove unnecessary function __vxge_hw_device_id_get.

Signed-off-by: Jon Mason <jon.mason@exar.com>
Signed-off-by: Ram Vepa <ram.vepa@exar.com>
Signed-off-by: David S. Miller <davem@davemloft.net>