mpc8313, signed fit: enable legacy image format on ids8313 board

mpc8313, signed fit: enable legacy image format on ids8313 board

Enable legacy image format with CONFIG_IMAGE_FORMAT_LEGACY
on the ids8313 board, as it uses signed FIT images for booting
Linux and need the legacy image format.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Kim Phillips <kim.phillips@freescale.com>
Cc: Michael Conrad <Michael.Conrad@ids.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>