[ONOS-4520] Separate model messages from service messages in ProtoBuf IDL.

- move ProtoBuf generated code in a package similar to ONOS models.

Change-Id: I5deb591094c2b8af2b22041da935567fc8dacd87
diff --git a/incubator/rpc-grpc/src/main/proto/Port.proto b/incubator/rpc-grpc/src/main/proto/Port.proto
index f32193c..0d9ed2e 100644
--- a/incubator/rpc-grpc/src/main/proto/Port.proto
+++ b/incubator/rpc-grpc/src/main/proto/Port.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-option java_package = "org.onosproject.grpc";
+option java_package = "org.onosproject.grpc.net";
 
 package Port;
 
@@ -22,7 +22,6 @@
   VIRTUAL = 6;
 }
 
-// TODO What are we going to do with more specific PortDescription ...
 message PortDescription {
   // PortNumber as String PortNumber#toString
   string port_number = 1;