dbus: Do not depend on the dbus daemon when using libdbus

systemd can cope without having a dbus-daemon present. This is the
way we want it to operate to conserve a bit of memory. Do not install
the dbus daemon by default. Not having a dbus daemon is breaking the
systemd color output right now but this is something that should be fixable.

recipes-fixes/dbus/dbus_sysmocom_systemd.inc

@@ -0,0 +1,5 @@
+PRINC = "1"
+
+# We do not want to install a dbus-daemon by default. systemd is using
+# dbus without the dbus-daemon being installed. Patch out the dbus daemon.
+RRECOMMENDS_${PN}-lib = ""

yocto-master/dbus_1.6.10.bbappend

@@ -0,0 +1 @@
+require recipes-fixes/${PN}/${PN}_sysmocom_systemd.inc