Update config.guess and config.sub scripts to latest versions.

Current version of config.guess may fail to detect host libc version,
which results in problems with configure when building gcc. Current patches
are removed. Patch to add support for ps2 is removed as it was discussed on
buildroot mailing list that it is no longer needed.

[Arnout: drop the 'improve uClibc' patch, update commit message, update to
more recent version, update README.]
Signed-off-by: Jouko Nikula <jouko.nikula@espotel.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>