Only run cinder jobs on cinder changes

We currently run multiple jobs that deploy cinder on changes
that have no relation to the service. This change modifies the
job to only run when we modify the cinder chart, test scripts,
or the zuul files themselves.

Change-Id: Ia188193929143cb6ae52266a5a87d2662626d42e

zuul.d/jobs-openstack-helm.yaml

@@ -73,6 +73,10 @@
 - job:
     name: openstack-helm-cinder
     parent: openstack-helm-chart-deploy
+    files:
+      - ^cinder/.*$
+      - ^zuul\.d/.*$
+      - ^tools/deployment/component/cinder/.
     vars:
       osh_params:
         openstack_release: train