This will allows elf loader to directly have an elf file available. Thus
filetype_elf bootm handlers will be able to use standard bootm functions
and data.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>