Hi @manvar-pratik,
Support for the STM32MP has been merged on kirkstone just a few days ago, and the dunfell integration is discussed here, seemingly also relatievly close to being finished. So by all means in terms of security (not shipping outdated/vulnerable software) and maintainability, I would strongly advise to upgrade. Plus, you can use mender-growfs-data then 
Greetz,
Josef