Description of problem:
Create a storage class with no parameters, dynamic provision failed

Version-Release number of selected component (if applicable):
openshift v3.7.0-0.146.0
kubernetes v1.7.6+a08f5eeb62

How reproducible:
Always

Steps to Reproduce:
1. Create a storage class with no parameters
2. Create a pvc which point this storage class
3. PVC would keep pending

Actual results:
$ oc get pvc
NAME      STATUS    VOLUME    CAPACITY   ACCESSMODES   STORAGECLASS   AGE
azpvc     Pending                                      sc-kytwu       4m

$ oc describe pvc azpvc
Name:		azpvc
Namespace:	kytwu
StorageClass:	sc-kytwu
Status:		Pending
Volume:		
Labels:		<none>
Annotations:	volume.beta.kubernetes.io/storage-class=sc-kytwu
		volume.beta.kubernetes.io/storage-provisioner=kubernetes.io/azure-disk
Capacity:	
Access Modes:	
Events:
  FirstSeen	LastSeen	Count	From				SubObjectPath	Type		Reason			Message
  ---------	--------	-----	----				-------------	--------	------			-------
  5m		5s		22	persistentvolume-controller			Warning		ProvisioningFailed	Failed to provision volume with StorageClass "sc-kytwu": Create Storage Account: p443172070, error: storage.AccountsClient#Create: Failure responding to request: StatusCode=400 -- Original Error: autorest/azure: Service returned an error. Status=400 Code="LocationRequired" Message="The location property is required for this definition."

Expected results:
PVC can be provisioned and bound

Master Log:
Oct 10 09:10:42 wehe-master-etcd-nfs-1 atomic-openshift-master-controllers: I1010 09:10:42.354472   21378 pv_controller.go:1337] failed to provision volume for claim "default/registry-pvc" with StorageClass "grs": azureDisk - Standard_GRS is not supported sku/storageaccounttype. Supported values are [Premium_LRS Standard_LRS]
Oct 10 09:10:44 wehe-master-etcd-nfs-1 atomic-openshift-node: I1010 09:10:44.225558   14737 kubelet_node_status.go:490] Using Node Hostname from cloudprovider: "wehe-master-etcd-nfs-1.eastus.cloudapp.azure.com"
Oct 10 09:10:44 wehe-master-etcd-nfs-1 atomic-openshift-master-api: I1010 09:10:44.240381   21352 rest.go:349] Starting watch for /api/v1/services, rv=2299 labels= fields= timeout=7m33s
Oct 10 09:10:49 wehe-master-etcd-nfs-1 atomic-openshift-master-controllers: I1010 09:10:49.692346   21378 azure_blobDiskController.go:602] azureDisk - Creating storage account p443172070 type Standard_LRS
Oct 10 09:10:49 wehe-master-etcd-nfs-1 atomic-openshift-master-controllers: I1010 09:10:49.733551   21378 pv_controller.go:1337] failed to provision volume for claim "kytwu/azpvc" with StorageClass "sc-kytwu": Create Storage Account: p443172070, error: storage.AccountsClient#Create: Failure responding to request: StatusCode=400 -- Original Error: autorest/azure: Service returned an error. Status=400 Code="LocationRequired" Message="The location property is required for this definition."
Oct 10 09:10:50 wehe-master-etcd-nfs-1 atomic-openshift-master-api: I1010 09:10:50.478416   21352 rest.go:349] Starting watch for /apis/network.openshift.io/v1/egressnetworkpolicies, rv=2254 labels= fields= timeout=6m6s
Oct 10 09:10:54 wehe-master-etcd-nfs-1 atomic-openshift-node: I1010 09:10:54.409112   14737 kubelet_node_status.go:490] Using Node Hostname from cloudprovider: "wehe-master-etcd-nfs-1.eastus.cloudapp.azure.com"
Oct 10 09:10:56 wehe-master-etcd-nfs-1 atomic-openshift-master-api: I1010 09:10:56.268606   21352 rest.go:349] Starting watch for /apis/extensions/v1beta1/networkpolicies, rv=19624 labels= fields= timeout=6m16s
Oct 10 09:10:56 wehe-master-etcd-nfs-1 atomic-openshift-master-api: I1010 09:10:56.652807   21352 rest.go:349] Starting watch for /apis/extensions/v1beta1/daemonsets, rv=19695 labels= fields= timeout=6m7s
Oct 10 09:10:56 wehe-master-etcd-nfs-1 atomic-openshift-node: I1010 09:10:56.905512   14737 qos_container_manager_linux.go:286] [ContainerManager]: Updated QoS cgroup configuration


Node Log (of failed PODs):

PV Dump:

PVC Dump:
$ oc export pvc azpvc
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  annotations:
    volume.beta.kubernetes.io/storage-class: sc-kytwu
    volume.beta.kubernetes.io/storage-provisioner: kubernetes.io/azure-disk
  creationTimestamp: null
  name: azpvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
status: {}

StorageClass Dump (if StorageClass used by PV/PVC):
# oc export storageclass sc-kytwu
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  creationTimestamp: null
  name: sc-kytwu
provisioner: kubernetes.io/azure-disk

Additional info:
From the master log, we can see another issue, sku name only support Premium_LRS Standard_LRS now, not sure whether this is new design for OCP