Bug#1110431: systemd-cryptsetup: please consider providing a .udeb

[Luca Boccassi]

Control: tags -1 wontfix
Control: close -1

udebs are a huge amount of work for everyone involved, especially the
already overworked D-I team, so I am not going to add new ones.

Any additional unlock method can simply be added later, it's fine to
create the volume with a passphrase first, and in fact there should
always be one as a backup.

Other methods can be enrolled either in the installer itself, after the
rootfs has been installed and using the packages and tools from
/target, or after first boot. There is no need to further complicate
the D-I image builds with more udebs.