Use configuration from Ubuntu arm64 as generic common ground and future common one.
I propose we do i by sections:
General setup -> # Networking options
Networking options -> # Character devices
Character devices - ># Media drivers
Media drivers -> # File systems
File systems -> end
Select your region
Add sub task named under chosen section
When you are done, make a PR
Goal is to get all family kernels as close as possible to each other and to upstream config. Of course family specifc and neccessary changes should remain. As some kernel features might break some boards it is especially important to open PR, test and discuss properly before merging.