mlx4: Add support for CONFIG_DEV command

Introduce the CONFIG_DEV firmware command which we will use to
configure the UDP port assumed by the firmware for the VXLAN offloads.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/ethernet/mellanox/mlx4/cmd.c
Simple merge

diff --cc drivers/net/ethernet/mellanox/mlx4/fw.c
Simple merge

diff --cc include/linux/mlx4/cmd.h
Simple merge

diff --cc include/linux/mlx4/device.h
Simple merge