Enable WQ creation and modification with cvlan stripping offload.
This includes:
- Adding WQ creation flags.
- Extending modify WQ to get flags and flags mask to enable turning
  it on and off.
Signed-off-by: NNoa Osherovich <noaos@mellanox.com>
Reviewed-by: NMaor Gottlieb <maorg@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>