[PATCH] allow gold subdir building for mips

[Cary Coutant]

> 2015-04-20  Mike Frysinger  <vapier@gentoo.org>
>
>         * configure.ac: Add mips*-*-* to the gold target check.
>         * configure: Regenerate.

I've been waiting for approval for this patch since October:

   https://gcc.gnu.org/ml/gcc-patches/2014-10/msg01946.html
   https://gcc.gnu.org/ml/gcc-patches/2014-10/msg03131.html
   https://gcc.gnu.org/ml/gcc-patches/2014-12/msg00108.html
   https://gcc.gnu.org/ml/gcc-patches/2015-02/msg00186.html

-cary