Update config.{guess,sub}

...to latest versions from <http://git.savannah.gnu.org/gitweb/?p=config.git;
a=blob_plain;f=config.guess;hb=HEAD> and <http://git.savannah.gnu.org/gitweb/?
p=config.git;a=blob_plain;f=config.sub;hb=HEAD>, for aarch64 support.

Change-Id: If4ed1a6ced85947ee5b1b923fd09b4d679140145