Remove references to openstack and cinder

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

cluster/addons/storage-class/openstack/default.yaml

@@ -1,9 +0,0 @@
-apiVersion: storage.k8s.io/v1
-kind: StorageClass
-metadata:
-  name: standard
-  annotations:
-    storageclass.kubernetes.io/is-default-class: "true"
-  labels:
-    addonmanager.kubernetes.io/mode: EnsureExists
-provisioner: kubernetes.io/cinder