ld-version: Fix it on Fedora

On Fedora 23, ld --version outputs:
GNU ld version 2.25-15.fc23

But ld-version.sh fails to parse this, so e.g.  mips build fails to
enable VDSO, printing a warning that binutils >= 2.24 is required.

To fix, teach ld-version to parse this format.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12023/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>