Update config.sub, config.guess and configure.

The motivation to do that:

1. Now, llvm would use the stock config.sub. Before that we had an
uncommitted FreeBSD-related patch. Now, it has been upstreamed and
comes back. It means that it would be easier to update these files in
the next time (less magic knowledge)

2. Fix a typo for pseudo-CPUs: 32e[lb] -> [lb]e32, 64e[lb]->[lb]64.
One of these CPUs is used for PNaCl and it was not really convenient
to have a CPU that starts with a digit.

llvm-svn: 138323