net/mlx5: Define interface bits for fencing UMR wqe

HW can implement UMR wqe re-transmission in various ways.
Thus, add HCA cap to distinguish the needed fence for UMR to make
sure that the wqe wouldn't fail on mkey checks.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>