Add option for dbus in configure.ac, and explicitly build without dbus
for rpm-native.
Previously, the rpm recipe tries to prevent rpm-native from attempting
to inhibit shutdown via session dbus by appending '--disable-plugins'
to EXTRA_OECONF in case of native.
However, some layer may need some functionality via plugin support. And
when it enables it, we would meet the following warning at rootfs time.
Unable to get systemd shutdown inhibition lock: Socket name too long
As plugins/systemd_inhibit.c is the only place that's related to this
dependency, we can be sure that dbus is really not needed for rpm-native.
Signed-off-by: Chen Qi <Qi.Chen@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
