[U-Boot] [PATCH] Allow for parallel builds and saved output

[Andy Fleming]

>> +             ${MAKE} clean
>> +             find "${output_dir}" -type f -name '*.depend' | xargs rm
>
> why not use distclean and avoid the `find` ?  otherwise, this find should be:
>        find "${output_dir}" -type f -name '*.depend' -exec rm -f {} +


distclean removes the u-boot executables. I thought it would be useful
to keep them around so one could theoretically test all of the systems
one built. I run make clean (which doesn't delete the results) and
delete the .depend files because otherwise one can very quickly fill
up a disk with ./MAKEALL powerpc