VOL-3367 - bump chart versions

Change-Id: I1ddcd04b62d44fda5c381c70a28b4df361155550
diff --git a/voltha-adapter-openolt/Chart.yaml b/voltha-adapter-openolt/Chart.yaml
index 456444b..da69f6c 100644
--- a/voltha-adapter-openolt/Chart.yaml
+++ b/voltha-adapter-openolt/Chart.yaml
@@ -14,7 +14,7 @@
 ---
 apiVersion: "v1"
 name: "voltha-adapter-openolt"
-version: "2.5.1"
+version: "2.5.7"
 description: "A Helm chart for Voltha OpenOLT Adapter"
 keywords:
   - "onf"