package/libmbim: Now needs libgudev under systemd

libmbim uses code (originally from udev) that has since been split
from the main systemd codebase into libgudev.

Fixes: http://autobuild.buildroot.org/results/638/638dbf05b785a276a33983b0237b7cad54777b85/

Tweak the package files for libmbim to require libgudev when building
with systemd.

Signed-off-by: Nathaniel Roach <nroach44@gmail.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libmbim/Config.in

@@ -3,6 +3,7 @@ config BR2_PACKAGE_LIBMBIM
 	depends on BR2_USE_WCHAR # libglib2
 	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib2
 	depends on BR2_PACKAGE_HAS_UDEV
+	select BR2_PACKAGE_LIBGUDEV if BR2_INIT_SYSTEMD
 	select BR2_PACKAGE_LIBGLIB2
 	help
 	  libmbim is a glib-based library for talking to WWAN modems and

package/libmbim/libmbim.mk

@@ -13,6 +13,10 @@ LIBMBIM_INSTALL_STAGING = YES
 
 LIBMBIM_DEPENDENCIES = libglib2 udev
 
+ifeq ($(BR2_INIT_SYSTEMD),y)
+LIBMBIM_DEPENDENCIES += libgudev
+endif
+
 # we don't want -Werror
 LIBMBIM_CONF_OPTS = --enable-more-warnings=no