spl: fit: Add booting OS first

If CONFIG_SPL_OS_BOOT is enabled, boot OS if kernel image is found
in FIT structure.

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