IB/core: Fix SM LID/LID change with client reregister set

After commit 12bbb2b7, when SM LID
change or LID change MAD also has a client reregistration bit set,
only CLIENT_REREGISTER event is generated.

As a result, the sa_query module and the cache module don't update the
port information, and ULPs (e.g. IPoIB) stop working.  This is the
regression we observe as compared to 2.6.17.

Rather than generate multiple events (which would have negative
performance impact), let us simply let cache and SA query respond to
reregister event in the same way as to LID and SM change events.

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