in-band: Use "internal" netdev type for local ports.

in-band: Use "internal" netdev type for local ports.

A bridge's local port always has type "internal", so opening it
with type "system" can't be correct.  This was causing upgrade
problems.  Specifically, in certain bridge topologies, if there was
a manager set force-reload-kmod would fail.  This is because the
local port netdev would open in the in-band code with type
"system", confusing the more important netdev_open() in
iface_create().

Bug #15067.
Signed-off-by: Ethan Jackson <ethan@nicira.com>