systemd: add option to enable kdbus support

In the future when the kernel offically supports kdbus, this option
should automatically enable the kernel kdbus config option(s).

Signed-off-by: Ryan Barnett <ryanbarnett3@gmail.com>
Tested-by: Mike Williams <mike@mikebwilliams.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/systemd/Config.in

@@ -73,6 +73,11 @@ config BR2_PACKAGE_SYSTEMD_ALL_EXTRAS
 	  Enable extra features for Systemd: journal compression and
 	  signing.
 
+config BR2_PACKAGE_SYSTEMD_KDBUS
+	bool "enable kdbus support"
+	help
+	  Enable kdbus support for Systemd.
+
 config BR2_PACKAGE_SYSTEMD_JOURNAL_GATEWAY
 	bool "HTTP server for journal events"
 	select BR2_PACKAGE_LIBMICROHTTPD

package/systemd/systemd.mk

@@ -71,6 +71,12 @@ else
 SYSTEMD_CONF_OPTS += --disable-seccomp
 endif
 
+ifeq ($(BR2_PACKAGE_SYSTEMD_KDBUS),y)
+SYSTEMD_CONF_OPTS += --enable-kdbus
+else
+SYSTEMD_CONF_OPTS += --disable-kdbus
+endif
+
 ifeq ($(BR2_PACKAGE_SYSTEMD_ALL_EXTRAS),y)
 SYSTEMD_DEPENDENCIES += xz libgcrypt
 SYSTEMD_CONF_OPTS += \