With Yocto, sadly no official support. Check this thread Yocto on milk-v duo
The meta-milkv layer uses the same kernel version as here but you can modify the kas-project.yml file to set the kernel with a line like this near the other machine config.
PREFERRED_PROVIDER_virtual/kernel = "linux-milkv-duo"
Beware though that there’s only basic mainline support in that branch, you’ll need to pull in the various patches from the wiki to get things like USB working.