VOL-1123 Specify serial number for Ponsim v2 ONU on command line

Change-Id: I85a15c0e710f22d2869fbe47976036cfa1ee610d
diff --git a/ponsim/v2/core/ponsim_onu.go b/ponsim/v2/core/ponsim_onu.go
index ac3a02a..ae40387 100644
--- a/ponsim/v2/core/ponsim_onu.go
+++ b/ponsim/v2/core/ponsim_onu.go
@@ -43,6 +43,7 @@
 	ParentAddress string
 	ParentPort    int32
 	AssignedPort  int32
+	SerialNumber  string
 	Conn          *grpc.ClientConn
 
 	oltClient ponsim.PonSimCommonClient
@@ -214,6 +215,7 @@
 				Id:      uuid.New().String(),
 				Address: common.GetInterfaceIP(o.InternalIf),
 				Port:    o.Port,
+				SerialNumber: o.SerialNumber,
 			}
 			common.Logger().Printf("Request details %+v\n", rreq)