1. Proposed title of this feature request
Support rebootless update of chrony.conf

2. What is the nature and description of the request?
I would like to update my NTP configuration (by applying MC that updates /etc/crony.conf) without all cluster nodes getting rebooted.
Similar to what MCO is currently doing for ssh keys
https://github.com/openshift/machine-config-operator/blob/8c9f1af45d1067e4f189b82cd2e9d2b487811021/docs/MachineConfigDaemon.md#rebootless-updates

3. Why does the customer need this? (List the business requirements here)
This would be useful for image based installation that need to support changes to NTP without rebooting the node.

4. List any affected packages or components.
MCO, MCD

github issue: https://github.com/openshift/machine-config-operator/issues/4375