IB/hfi1: Send a pkey change event on driver pkey update

Swapping a cable from a "Mgmt Allowed=No" switch port to a
"Mgmt Allowed=Yes" switch port doesn't send a pkey change
notification. Therefore, the link doesn't become active as
the oib_utils layer uses an old pkey table cache.

Fix by ensuring the pkey change notification is sent when
the table is changed both explicitly by the FM and implicitly
by the driver via a cable swap.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>