netdev: Allow storing dpif type into netdev structure.

netdev: Allow storing dpif type into netdev structure.

Storing of the dpif type of the owning datapath interface will allow
us to easily distinguish, for example, userspace tunneling ports from
the system ones.  This is required in terms of HW offloading to avoid
offloading of userspace flows to kernel interfaces that doesn't belong
to userspace datapath, but have same dpif_port names.

Acked-by: Eli Britstein <elibr@mellanox.com>
Acked-by: Roni Bar Yanai <roniba@mellanox.com>
Acked-by: Ophir Munk <ophirmu@mellanox.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>