ofagent: Support physical_interface_mappings

Also, add a knob to create a veth pair instead of a bridge
to provide host connectivity for l3-agent.  (Q_USE_PUBLIC_VETH)

Related: blueprint ofagent-physical-interface-mappings
Change-Id: I4c2538f0fd3fb05bfdb69e7e4c3a8462af42ba10
diff --git a/lib/neutron_plugins/ofagent_agent b/lib/neutron_plugins/ofagent_agent
index a5a58f4..1c04f2f 100644
--- a/lib/neutron_plugins/ofagent_agent
+++ b/lib/neutron_plugins/ofagent_agent
@@ -77,6 +77,10 @@
     if [[ "$OVS_BRIDGE_MAPPINGS" != "" ]]; then
         iniset /$Q_PLUGIN_CONF_FILE ovs bridge_mappings $OVS_BRIDGE_MAPPINGS
     fi
+    if [[ "$OFAGENT_PHYSICAL_INTERFACE_MAPPINGS" != "" ]]; then
+        iniset /$Q_PLUGIN_CONF_FILE agent physical_interface_mappings \
+            $OFAGENT_PHYSICAL_INTERFACE_MAPPINGS
+    fi
     AGENT_BINARY="$NEUTRON_BIN_DIR/neutron-ofagent-agent"
 
     iniset /$Q_PLUGIN_CONF_FILE agent tunnel_types $Q_TUNNEL_TYPES