Add SALT_OVERRIDES to deploy jobs

Change-Id: Ia9f05ca26a31d5cb08bd9bbba82a41742b0105a8
diff --git a/jenkins/client/job/deploy/lab/mk/init.yml b/jenkins/client/job/deploy/lab/mk/init.yml
index 996400e..3db11b8 100644
--- a/jenkins/client/job/deploy/lab/mk/init.yml
+++ b/jenkins/client/job/deploy/lab/mk/init.yml
@@ -77,6 +77,10 @@
               SALT_MASTER_URL:
                 type: string
                 default: ""
+             SALT_OVERRIDES:
+                type: text
+                default: ""
+                description: "YAML with overrides for Salt deployment"
 
               # openstack api
               OPENSTACK_API_URL: