The XO-1 laptop has a NAND flash and firmware capable of reading JFFS2
from it. Enable JFFS2 kernel support so that we'll be able to create
images capable of booting from the internal flash.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>