For non-XOS charts, use a global registry var, split docker image name/tag/pullPolicy

Change-Id: Icffc569e2c152e0b413f4c7b7d9a546bd9a3ef58
diff --git a/dhcp-server/templates/deployment.yaml b/dhcp-server/templates/deployment.yaml
index 95a3b03..4a63279 100644
--- a/dhcp-server/templates/deployment.yaml
+++ b/dhcp-server/templates/deployment.yaml
@@ -1,3 +1,4 @@
+---
 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -27,8 +28,8 @@
     spec:
       containers:
         - name: dhcp-server
-          image: {{ .Values.dhcpServerImage }}
-          imagePullPolicy: {{ .Values.imagePullPolicy }}
+          image: {{ .Values.global.registry }}{{ .Values.image.repository }}:{{ tpl .Values.image.tag . }}
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
           #command: ["/bin/bash", "-", "sleep 86400"]
           ports:
             - containerPort: 67