The name CONFIG_LEGACY_IMAGE_FORMAT reads slightly better along with
allowing us to avoid a rather nasty Kbuild/Kconfig issue down the line
with CONFIG_IS_ENABLED(IMAGE_FORMAT_LEGACY). In a few places outside of
cmd/ switch to using CONFIG_IS_ENABLED() to test what is set.
Signed-off-by: Tom Rini <trini@konsulko.com>
c76c93a3d5