[CT-NG:patch 05/19] Force autoreconf for mpfr

In some exotic case the autoreconf step of mpfr is not executed (correctly)
leaving an incorrect version number for libtool in the configure script.

After extracting the sources files, force autoreconf to be executed.

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>

 # m68k specific configuration file

 # depends on EXPERIMENTAL

 config ARCH_m68k

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_DEFAULT_BE

     select ARCH_SUPPORT_CPU

      help

       The m68k architecture