Referencing nginx base image in voltha values.yaml

Change-Id: Iacf25838057f9f8fab2633ba17c1c2a3dc19255c
diff --git a/voltha/values.yaml b/voltha/values.yaml
index 319685e..ee2f720 100644
--- a/voltha/values.yaml
+++ b/voltha/values.yaml
@@ -103,6 +103,10 @@
     tag: '0.10.2'
     pullPolicy: 'Always'
 
+  ingress_controller_base:
+    repository: 'alpine'
+    tag: '3.6'
+    pullPolicy: 'Always'
 
 # Need the namespace global for kafka
 global: