drop support for multiple kernel flavors
Similar to the postmarketos-mkinitfs issue pmaports#660 (closed): we have support for multiple kernel flavors in pmbootstrap, but it doesn't really make sense. So it just makes code paths mode complicated and should be simplified.
A lot of pmbootstrap actions have --flavor
arguments that could be removed - since nobody is using that, it might even be broken currently. There's the whole pmbootstrap initfs ...
, most subcommands have --flavor
arguments too.