ONOS-6561 BMv2 handshaker via P4Runtime

+ support fort device-specific default pipeconf
+ improvements to P4runtime and gRPC protocol stuff

Change-Id: I8986fce3959df564454ea3d31859860f61eabcae
diff --git a/tools/dev/mininet/bmv2.py b/tools/dev/mininet/bmv2.py
index e1d51a5..a0f92d2 100644
--- a/tools/dev/mininet/bmv2.py
+++ b/tools/dev/mininet/bmv2.py
@@ -79,9 +79,13 @@
                         "p4runtime": {
                             "ip": srcIP,
                             "port": self.grpcPort,
+                            "deviceId": self.deviceId,
                             "deviceKeyId": "p4runtime:%s" % onosDeviceId
                         }
                     },
+                    "piPipeconf": {
+                        "piPipeconfId": ""
+                    },
                     "basic": {
                         "driver": "bmv2"
                     }