Reported by Grant Edwards <grant.b.edwards@gmail.com>
Use the new default STAGING_DIR location (output/staging) in all the
defconfigs for clarity.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
As discussed earlier on the mailing list. It simplifies code, gives more
sensible error message on typos and makes the defconfigs easier to find
for users.
Furthermore, update documentation to match.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
