Fix ntp conf template name in host-upgrade.pp

After merging ntp puppet module with mainstream template file
for configuration changed name.

Change-Id: I9ecfe32d111dccbbe53e4ac8688428a52c2de9f4
Related: blueprint merge-openstack-puppet-modules
Related: I8f9ac3bdacbd5512224bb4b1a5b9214bed54093c
Related: I0ceb392d8750469ece3c93d67d2c73a8a6d7b71d
Closes-Bug: #1388049
Merge "Fix ntp conf template name in host-upgrade.pp"