cephfs-provisioner: Upgrade to v2.1.0-k8s1.11

Upstream Changes:

-   cephfs-provisioner v2.1.0-k8s1.11 (https://github.com/kubernetes-incubator/external-storage/releases/tag/cephfs-provisioner-v2.1.0-k8s1.11)

Our Changes:

-   Sync clusterrole and role with upstream changes