when mixing dpdk & non-dpdk OVS with the same ODL - no way to configure different datapath types

Old netvirt iterated over the interfaces in bridge, and set the bridge type to netdev if it found a dpdk interface.

New vpnservice netvirt has a configuration flag (ovsdb.userspace.enabled) to determine the same (this is problematic as it doesn't allow usage of different types of OVS)

The first option isn't ideal because we might have br-int bridge that has no dpdk port, but has a patch port connected with dpdk bridge, and thus has to be a dpdk bridge as well.