Bump voltha-openolt-adapter chart version to 2.5.10 for voltha-2.4 release

Change-Id: Ifc4105ab7d614e36e9055ab1918f50e7d78823b8
diff --git a/releases/voltha-2.4 b/releases/voltha-2.4
index fdc27c0..2f294f6 100644
--- a/releases/voltha-2.4
+++ b/releases/voltha-2.4
@@ -5,7 +5,7 @@
 
 export VOLTHA_CHART_VERSION=2.5.7
 export VOLTHA_BBSIM_CHART_VERSION=3.1.0
-export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.9
+export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.10
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.4.6
 export ONOS_CLASSIC_CHART_VERSION=0.1.1
 export RADIUS_CHART_VERSION=1.0.1