Add stub for GetPonIf

Change-Id: I0a40d0ca5271d49e848466994ab4dc59704b3c40
diff --git a/protos/openolt.proto b/protos/openolt.proto
index 9fa9566..6be8983 100644
--- a/protos/openolt.proto
+++ b/protos/openolt.proto
@@ -103,6 +103,13 @@
         };
     }
 
+    rpc GetPonIf(Interface) returns (IntfIndication) {
+        option (google.api.http) = {
+            post: "/v1/GetPonIf"
+            body: "*"
+        };
+    }
+
     rpc DisablePonIf(Interface) returns (Empty) {
         option (google.api.http) = {
             post: "/v1/DisablePonIf"