[OE-core] dbus: only use x11 if DISTRO_FEATURES has selected it

[James Limbouris]

Hi,

I was trying to take advantage of the new x11 DISTRO_FEATURE and
ran into some trouble with the dbus package. When building with meta-oe,
gconf depends on dbus-x11, and just about everything depends on gconf.
So when I disable x11, I can only build my images with 'bitbake -I dbus-x11'.

As it turns out, the files shipped in dbus-x11 are still built even when the
--without-x option is used. Perhaps it would be better to allow them to
be packaged, even without x11 support?
  
James