net/mlx4_core: Keep VF assigned MAC in the PF admin table

MAC addresses assigned by the PF to VFs were not kept in the PF driver
admin table. As a result, displaying the VF MACs from the PF interface
to user space showed zero address where in fact the VF got non-zero
address from the PF, fix that.

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