Using updated openolt chart for 2.4

Change-Id: Ib3637452af49bd9b7f8ad198b5badda52cec0b7a
diff --git a/VERSION b/VERSION
index f8ee15f..831446c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.1.0-dev
+5.1.0
diff --git a/releases/voltha-2.4 b/releases/voltha-2.4
index f110a55..e5e862a 100644
--- a/releases/voltha-2.4
+++ b/releases/voltha-2.4
@@ -5,7 +5,7 @@
 
 export VOLTHA_CHART_VERSION=2.5.2
 export VOLTHA_BBSIM_CHART_VERSION=3.0.28
-export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.2
+export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.3
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.4.2
 export ONOS_CLASSIC_CHART_VERSION=0.1.1
 export RADIUS_CHART_VERSION=1.0.0