Reset in_port for provider ingress packets
Reset in_port for provider ingress packets

This change clears in_port on packets arriving from flat/vlan networks,
to allow installation of ARP responders for local ports on
aforementioned networks.

Additionally, a new flow is added to EGRESS_TABLE to drop all broadcast
packets duplicate by L2 app.

Change-Id: I45fd044a9823342406e4665ba6325ff7821bdd48

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow