The bootstd code itself does not have any dependency on BLK in order to build. However, in order to minimize size growth of non-migrated platforms, change this from being "default y" to "default y if BLK". This will make it easier to begin migration of platforms which do not have any BLK-class device but do want to use bootstd. Signed-off-by: Tom Rini <trini@konsulko.com>