image: use data base addr for image_print_contents, image_multi_count/getimg
as in barebox the data could be the mapped file or a allocated memory with
just the data (non header)
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>