Reducing duplicated values on values files for SiaB

Reduced the amount of duplicated values between seba-ponsim values file.
To deploy, for example, the latest of seba-ponsim, now both seba-ponsim.yaml and seba-pomsim-latest.yaml values files need to be used with the specified order.
Makefile for SiaB is modified accordingly in the patch https://gerrit.opencord.org/#/c/16743/.
Also:
- removed stratumEnabled value from Mininet chart and added mnStratumSwitchCount
- moved bngAppUrl and bngAppVersion values on root of values file

Change-Id: I26b8e91f868646adc06f2c1feea72b333defd487
diff --git a/xos-profiles/seba-services/values.yaml b/xos-profiles/seba-services/values.yaml
index 551ae3f..eccad87 100644
--- a/xos-profiles/seba-services/values.yaml
+++ b/xos-profiles/seba-services/values.yaml
@@ -52,6 +52,9 @@
 kafkaAppUrl: "https://oss.sonatype.org/content/groups/public/org/opencord/kafka/2.0.0/kafka-2.0.0.oar"
 kafkaAppVersion: "2.0.0"
 
+bngAppUrl: "https://oss.sonatype.org/content/groups/public/org/opencord/bng/1.0.0/bng-1.0.0.oar"
+bngAppVersion: "1.0.0"
+
 onosRestService: "onos-ui.default.svc.cluster.local"
 kafkaService: "cord-kafka.default.svc.cluster.local:9092"
 
@@ -81,6 +84,3 @@
     enabled: true
   embedded:
     enabled: false
-    bngAppId: "org.opencord.bng"
-    bngAppUrl: "https://oss.sonatype.org/content/groups/public/org/opencord/bng/1.0.0/bng-1.0.0.oar"
-    bngAppVersion: "1.0.0"