IB/mlx4: Set VF to read from QP counters

As IB VFs are not capable to read the port counters through MADs,
move there to read their own QP counters to gather statistics.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>