spl: fit: Support both external and embedded data

SPL supports U-Boot image in FIT format which has data outside of
FIT structure. This adds support for embedded data for normal FIT
images.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2 files changed