util/crossgcc: Bump GMP version to 6.1.0

The previous official GMP release (6.0.0) contains a bug that
prevents compilation on ppc64el systems.  Increase version
to the latest version (6.1.0).

Bug details:

gcc build on ppc64el fails with:
(.text+0x4c): undefined reference to `BMOD_1_TO_MOD_1_THRESHOLD'

While I don't have an exact commit hash due to Hg use upstream,
a missing BMOD_1_TO_MOD_1_THRESHOLD define on ppc64el was quietly
fixed in Hg before the 6.1.0 release.

Change-Id: I1c05a1c194141db5f8522148c2e20e7558d34714
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/12811
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

util/crossgcc/buildgcc

@@ -31,7 +31,7 @@ SAVETEMPS=0
 SKIPPYTHON=1
 
 # GCC toolchain version numbers
-GMP_VERSION=6.0.0
+GMP_VERSION=6.1.0
 MPFR_VERSION=3.1.2
 MPC_VERSION=1.0.3
 LIBELF_VERSION=0.8.13
@@ -46,7 +46,7 @@ EXPAT_VERSION=2.1.0
 CLANG_VERSION=3.6.1
 
 # GCC toolchain archive locations
-GMP_ARCHIVE="http://ftpmirror.gnu.org/gmp/gmp-${GMP_VERSION}a.tar.bz2"
+GMP_ARCHIVE="http://ftpmirror.gnu.org/gmp/gmp-${GMP_VERSION}.tar.bz2"
 MPFR_ARCHIVE="http://ftpmirror.gnu.org/mpfr/mpfr-${MPFR_VERSION}.tar.bz2"
 MPC_ARCHIVE="http://ftpmirror.gnu.org/mpc/mpc-${MPC_VERSION}.tar.gz"
 LIBELF_ARCHIVE="http://www.mr511.de/software/libelf-${LIBELF_VERSION}.tar.gz"

util/crossgcc/sum/gmp-6.0.0a.tar.bz2.cksum

@@ -1 +0,0 @@
-360802e3541a3da08ab4b55268c80f799939fddc  tarballs/gmp-6.0.0a.tar.bz2

util/crossgcc/sum/gmp-6.1.0.tar.bz2.cksum

@@ -0,0 +1 @@
+db38c7b67f8eea9f2e5b8a48d219165b2fdab11f  tarballs/gmp-6.1.0.tar.bz2