Add functions to read the barebox_arm_head, check barebox magicword
and read out the barebox image size.
Create a inital partion of 1Mb to access the barebox image on nand.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>