mlx4_core: use correct port for steering

Use port number for correct steering (list per port).
Before the fix all steering entries (for both physical ports)
were managed in first port structures, so we had leakage of resources
for port 2.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>