Bumping voltha core chart

Change-Id: I6d4acc47e50d362cda06944875f2d85c20d7eefa
diff --git a/voltha/values.yaml b/voltha/values.yaml
index 09e3942..37596d1 100644
--- a/voltha/values.yaml
+++ b/voltha/values.yaml
@@ -102,5 +102,5 @@
   rw_core:
     registry: '{{ .Values.defaults.image_registry }}'
     repository: '{{ .Values.defaults.image_org }}voltha-rw-core'
-    tag: '{{- if hasKey .Values.defaults "image_tag" }}{{- if .Values.defaults.image_tag }}{{ .Values.defaults.image_tag }}{{- else }}2.5.3{{- end }}{{- else }}2.5.3{{- end }}'
+    tag: '{{- if hasKey .Values.defaults "image_tag" }}{{- if .Values.defaults.image_tag }}{{ .Values.defaults.image_tag }}{{- else }}2.5.4{{- end }}{{- else }}2.5.4{{- end }}'
     pullPolicy: '{{ .Values.defaults.image_pullPolicy }}'