package/systemd: use host-systemctl preset all to enable units

package/systemd: use host-systemctl preset all to enable units

since v234 upstream recommands using systemctl preset-all to enable units.
* add a buildroot specific preset file
* use that file to disable getty@tty1
* make systemd depend on host-systemd
* remove all link-creating code that systemd does for us.

Most packages will not be affected by this change, but a few packages
were installing units without manually enabling them. Those packages
will now be automatically enabled.

The fact that those packages were not enabled is almost certainly a bug,
but it is a change of behaviour that needs to be reported

host-systemd also builds udevadm for the host. That means we no longer
need to depend on host-eudev to provide udevadm (that would conflict).

Signed-off-by: Jérémy Rosen <jeremy.rosen@smile.fr>
[yann.morin.1998@free.fr:
  - also remove the hwdb sources on fs generation
  - fix check-package errors
  - few typoes and reformatting in commit log
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>