bridge: open_type should be used for netdev_open

bridge: open_type should be used for netdev_open

ofproto_port_open_type should be used for netdev_open, but not for other tests.
For example, STP/RSTP check for interfaces of internal type, but that check will
fail when the netdev datapath is used.

The same thing goes for setting MAC address of internal Interfaces. That fails
for the netdev datapath because the interface type is set to "tap", but they are
still interfaces of type "internal", just their netdev implementation is
different.

Use a netdev_type for the type that needs to be used for netdev_open and
ofproto_port, while we still keep the type as the normalized configured type in
the database.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Jesse Gross <jesse@kernel.org>