IB/ipath: Fix IB_EVENT_PORT_ERR event

The link state event calls were being generated when the SM told the SMA
to change link states. This works for IB_EVENT_PORT_ACTIVE but not if
the link goes down and stays down. The fix is to generate event calls
from the interrupt handler when the HW link state changes.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>