Rather than implement this as its own case in build_order(), process the
boot_targets environment variable in the bootstd_get_bootdev_order()
function. This allows build_order() to be simplified.
Signed-off-by: Simon Glass <sjg@chromium.org>
The 'bootstd' device provides the central information about U-Boot
standard boot.
Add a uclass for bootstd and the various helpers needed to make it
work. Also add a binding file.
Signed-off-by: Simon Glass <sjg@chromium.org>
