Add support for running SiaB with stratum_bmv2 as the fabric switch

- new value file (seba-ponsim-stratum.yaml) to deploy SiaB with Stratum
- new mininet script to use stratum_bmv2 instead of OVS as Fabric switch
- update to ponsim and mininet to use the new Stratum device instead of OVS

Change-Id: I35901b455865cebc0a11de8b155b951e4fa4a9f8
diff --git a/mininet/templates/deployment.yaml b/mininet/templates/deployment.yaml
index 0f1807d..90d54b2 100644
--- a/mininet/templates/deployment.yaml
+++ b/mininet/templates/deployment.yaml
@@ -40,7 +40,10 @@
         - name: {{ .Chart.Name }}
           image: "{{ .Values.global.registry }}{{ .Values.images.mininet.repository }}:{{ tpl .Values.images.mininet.tag . }}"
           imagePullPolicy: {{ .Values.images.mininet.pullPolicy }}
-          args: ["/toposcripts/topo.py"]
+{{- if $.Values.stratumEnabled }}
+          command: ["python"]
+{{- end }}
+          args: [{{ .Values.topoScript }}]
           stdin: true
           tty: true
           securityContext: