net/mlx5: E-switch, Supporting setting devlink port function mac address

Enable user to set mac address of the PCI PF and VF port function.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>