The end-at-4gb property implies a value for skip-at-start so add it into
the output FDT so that U-Boot can read it.
Now that skip-at-start is implemented, we can drop the workarounds used
in the x86 code to obtain the correct image-pos value.
Signed-off-by: Simon Glass <sjg@chromium.org>
92d5d1e1cd