package/x11r7/xlib_libXxf86dga: needs MMU

Fixes
http://autobuild.buildroot.net/results/f8f/f8f0b6cf9af21ff7d9ac76e670a7735ee9753315/
http://autobuild.buildroot.net/results/579/579e6db79929910ac53a914f65fc398a483134ae/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/x11r7/xlib_libXxf86dga/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_XLIB_LIBXXF86DGA
 	bool "libXxf86dga"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_XLIB_LIBX11
 	select BR2_PACKAGE_XLIB_LIBXEXT
 	select BR2_PACKAGE_XPROTO_XF86DGAPROTO