Deprecate the dvr_extra_resources config switch.

It was added to support the Liberty Release which we don't support
anymore.

Change-Id: I832923ee930f11111623583854ae2511f70f2dd2
diff --git a/releasenotes/notes/deprecate-dvr_extra_resources-config-8c319d6dab7f7e5c.yaml b/releasenotes/notes/deprecate-dvr_extra_resources-config-8c319d6dab7f7e5c.yaml
new file mode 100644
index 0000000..c3e43ee
--- /dev/null
+++ b/releasenotes/notes/deprecate-dvr_extra_resources-config-8c319d6dab7f7e5c.yaml
@@ -0,0 +1,7 @@
+---
+deprecations:
+  - |
+    The ``dvr_extra_resources`` configuration switch from the ``config`` module
+    is deprecated. It was added to support the Liberty Release which we don't
+    support anymore.
+
diff --git a/tempest/config.py b/tempest/config.py
index 3ad7684..74b7d16 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -606,7 +606,10 @@
                      "in L3 agent scheduler test. Extra resources need to be "
                      "provisioned in order to bind router to L3 agent in the "
                      "Liberty release or older, and are not required since "
-                     "the Mitaka release.")
+                     "the Mitaka release.",
+                deprecated_for_removal=True,
+                deprecated_reason='This config switch was added for Liberty '
+                                  'which is not supported anymore.')
 ]
 
 network_feature_group = cfg.OptGroup(name='network-feature-enabled',