integrate meta packages and change prefix

integrate meta packages and change prefix

long overdue, and avoids the issue of the meta packages version going down
after being folded in from the pve-kernel-meta repository.

the ABI needs to be bumped for every published kernel package now that modules
are signed, else the booted kernel image containing the public part of the
ephemeral signing key, and the on-disk (potentially upgraded in-place) signed
module files can disagree, and module loading would fail.

not changed (yet): git repository name, pve-firmware

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>