A couple bits are used by OPA for link physical state that are not present
as part of InfiniBand. Add a short blurb what those states mean and removed
an unused state.

Cc: Leon Romanovsky <leon@kernel.org>
Reviewed-by: NTodd Rimmer <todd.rimmer@intel.com>
Reviewed-by: NBrent Rothermel <brent.r.rothermel@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>