complibs/ppl: fix PPL build with GMP 5.x.x

From http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commitdiff;h=9c19bc2b318a35016e0189f9552c98910be37f53

Author: Roberto Bagnara <bagnara@cs.unipr.it>
Revision log: Added support for GMP 5.0.

Adapted manually to match and not having to re-generate the configure script.

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>

 # Blackfin specific configuration file

 config ARCH_blackfin

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_DEFAULT_LE

     select ARCH_SUPPORT_ARCH

     select ARCH_SUPPORT_CPU

     select ARCH_SUPPORT_TUNE

     select ARCH_SUPPORT_FPU

      help

       The Blackfin architecture