VOL-1796 make the log level a chart parameter

Change-Id: Ia42e91ebe1028d0a3f1829dd07e5203784dec0e7
diff --git a/voltha/values.yaml b/voltha/values.yaml
index 6429af9..32de22e 100644
--- a/voltha/values.yaml
+++ b/voltha/values.yaml
@@ -19,6 +19,7 @@
 
 # Default overrides
 defaults:
+  log_level: "ERROR"
   image_registry: ''
   image_tag: '{{ .Chart.AppVersion }}'
   image_org: "voltha/"
@@ -73,7 +74,11 @@
   afrouter: 1
   afrouterd: 1
 
+ro_core:
+  log_level: '{{ .Values.defaults.log_level }}'
+
 rw_core:
+  log_level: '{{ .Values.defaults.log_level }}'
   core_timeout: '{{ .Values.defaults.rw_core.timeout }}'
   timeout_long_request: '{{ .Values.defaults.rw_core.timeout }}'
   timeout_request: '{{ .Values.defaults.rw_core.timeout }}'