package/pkg-generic.mk: support hooks and tables in virtual packages
Virtual packages are not built but it's useful to allow them to have
permission/device/user tables and target-finalize/rootfs-pre-cmd hooks.
With this change we don't need to duplicate data as currently done in
eudev and systemd user tables, or test if the package is selected to add
a target-finalize hook as in luainterpreter.
Signed-off-by: Carlos Santos <unixmania@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>