Make onos service name configurable

Change-Id: I799ed24d461909a90fc334acfb51184d3932a42a
diff --git a/mininet/values.yaml b/mininet/values.yaml
index 68d914d..32a6fea 100644
--- a/mininet/values.yaml
+++ b/mininet/values.yaml
@@ -46,4 +46,6 @@
         topologyKey: kubernetes.io/hostname
 
 annotations:
-  cni: "calico,pon1"
\ No newline at end of file
+  cni: "calico,pon1"
+
+onosOpenflowSvc: "onos-openflow.default.svc.cluster.local"