Add RBAC examples for nfs-client

Adds example configuration files for clusters that have RBAC enabled
(1.6) or OpenShift users.

This is mostly a cut and paste job from the EFS example.

(cherry picked from commit a82645d4ec)

deploy/auth/clusterrolebinding.yaml

@@ -0,0 +1,12 @@
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1alpha1
+metadata:
+  name: run-nfs-client-provisioner
+subjects:
+  - kind: ServiceAccount
+    name: nfs-client-provisioner
+    namespace: default
+roleRef:
+  kind: ClusterRole
+  name: nfs-client-provisioner-runner
+  apiGroup: rbac.authorization.k8s.io