[IB] mthca: Fill in more fields in query_port method

Add code to fill in the bad_pkey_cntr, max_mtu, active_mtu and
subnet_timeout fields in mthca_query_port().

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>