Using released Voltha-onos 4.2.0

Change-Id: I6cb27ea606b5b48fc26d47be2f9c8ceeafa2d22d
diff --git a/releases/voltha-2.6 b/releases/voltha-2.6
index e3c175e..d5c43aa 100644
--- a/releases/voltha-2.6
+++ b/releases/voltha-2.6
@@ -1,7 +1,7 @@
 # SPDX-FileCopyrightText: © 2020 kind-voltha contributors
 # SPDX-License-Identifier: Apache-2.0o
 #
-# Source this file before running ./voltha up to install the VOLTHA 2.5.0 release
+# Source this file before running ./voltha up to install the VOLTHA 2.6.0 release
 
 export VOLTHA_CHART_VERSION=2.7.2
 export VOLTHA_BBSIM_CHART_VERSION=4.1.6
@@ -19,5 +19,4 @@
 # kind-voltha's default which is 'master'.
 # Also we need to specify the tag for voltha/voltha-onos image since this is
 # not in the ONOS chart.
-# NOTE we are waiting for voltha-onos to be releases (needs an ONOS release)
-export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=master "
+export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=4.2.0 "