openshift.ks: Doc CONF_NO_NTP/CONF_NO_SSH_KEYS

Document the CONF_NO_NTP and CONF_NO_SSH_KEYS options.
Merge pull request #42 from Miciah/openshift.ks-comment-CONF_NO_NTP-and-CONF_NO_SSH_KEYS

openshift.ks: Document the CONF_NO_NTP and CONF_NO_SSH_KEYS options