IB/mlx4: Implement ib_device callbacks

get_netdev: get the net_device on the physical port of the IB transport port. In
port aggregation mode it is required to return the netdev of the active port.

modify_gid: note for a change in the RoCE gid cache. Handle this by writing to
the harsware GID table. It is possible that indexes in cahce and hardware tables
won't match so a translation is required when modifying a QP or creating an
address handle.

Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index fd13c1c..5c7687a 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -79,7 +79,8 @@
 
 enum {
 	MLX4_MAX_PORTS		= 2,
-	MLX4_MAX_PORT_PKEYS	= 128
+	MLX4_MAX_PORT_PKEYS	= 128,
+	MLX4_MAX_PORT_GIDS	= 128
 };
 
 /* base qkey for use in sriov tunnel-qp/proxy-qp communication.