directfb: remove cle266 and unichrome support

They're broken for the latest version and directfb upstream is gone.

cle266 is an old chipset for AMD K7 (32 bit) athlons with integrated
graphics - very odd hardware.

unichrome is another VIA graphics standalone chip/chipset used for some
odd video cards and VIA CPUs (x86-based: C7, Nano and so on).

Add options to legacy as well. Fixes:

http://autobuild.buildroot.net/results/ab9/ab9a6dd044b5f3e8e42629a2aaf598fd0e0357ed/



Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>