buildroot

cups: deprecate package due to security issues

Also mark packages that depend on cups as deprecated as well for easier
tracking.

It would probably be better to mark it as a legacy option so users get a
warning when migrating configuration files, but it would require a
direct removal for that.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>