Configure NTP for overcloud compute

Updates the overcloud nova-compute templates so that
the NTP server is properly configured.

Change-Id: I4fc407153da5e031dcf5e5e5e1b3b74d932dba45
Partial-bug: #1309677

nova-compute-config.yaml

@@ -45,6 +45,9 @@ Resources:
           base_image_id: {get_input: nova_image}
           live_update_image_id: {get_input: live_update_compute_image}
         completion-signal: {get_input: deploy_signal_id}
+        ntp:
+          servers:
+              - {server: {get_input: ntp_server}, fudge: "stratum 0"}
   NovaComputePassthrough:
     Type: OS::Heat::StructuredConfig
     Properties:

nova-compute-instance.yaml

@@ -58,6 +58,9 @@ Parameters:
   NovaImage:
     Type: String
     Default: overcloud-compute
+  NtpServer:
+    Type: String
+    Default: ''
   KeystoneHost:
     Type: String
   NeutronFlatNetworks:
@@ -200,6 +203,7 @@ Resources:
         live_update_tenant_name: {Ref: LiveUpdateTenantName}
         nova_image: {Ref: NovaImage}
         live_update_image_id: {Ref: LiveUpdateComputeImage}
+        ntp_server: {Ref: NtpServer}
   NovaCompute0Passthrough:
     Type: OS::Heat::StructuredDeployment
     Properties: