sp-cinder: Enable run_validation in Tempest also in the iSCSI job

Change-Id: I6309ab5ab1e74d7aaa0ff714778427f7f7bf0551
diff --git a/zuul.d/sp-cinder.yaml b/zuul.d/sp-cinder.yaml
index aab46e1..0db024c 100644
--- a/zuul.d/sp-cinder.yaml
+++ b/zuul.d/sp-cinder.yaml
@@ -161,6 +161,10 @@
         TEMPEST_STORAGE_PROTOCOL: storpool
         ENABLE_VOLUME_MULTIATTACH: true
       devstack_local_conf:
+        test-config:
+          $TEMPEST_CONFIG:
+            validation:
+              run_validation: true
         post-config:
           $CINDER_CONF:
             storpool: