I recently pulled initramfs logic out of the base build hook, and
dropped that into the `replace_kernel` function. Any cloud image that
does not leverage the generic virtual kernel was expected to call
`replace_kernel` to pull in a custom kernel. That function will
disable initramfs boot for images that use a custom kernel.
Minimal cloud images on amd64 use the linux-kvm kernel, but the build
hook does not utilize the `replace_kernel` function. Instead, the
kernel flavor is set in `auto/config`. I pulled that logic out of
`auto/config` and am now calling `replace_kernel` in the build hook.
I also moved a call to generate the package list so that it will pick
up the change to the linux-kvm kernel.