We don't want to launch the dbus-daemon and we did this by modifying
the RDEPENDS_${PN}. Back then this was okay as dbus was the only
dependency but now kmod got added to the recipe as well. Use the new
language construct to just remove a specific value from the rdepends.
Paul Eggleton was nice enough to point that out.
Fixes: SYS#231
Provide custom systemd config files to enable the watchdog handling. For
systemd we depend on the image containing and using systemd as init script.
In case we build images without systemd we will need to install the
old watchdog. Maybe it is time to create a MACHINE_FEATURE for watchdog.