GTK+ needs either X11 or DirectFB, and fails with obscure errors if neither are present.
(From OE-Core rev: d308e4750e6647c2f2be9c69e25645d3eeb78b3f)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>