configure: s390x supports mttcg now

s390x is ready. Most likely we are missing some pieces, but it should
already be in pretty good shape now.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180129125623.21729-16-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/configure b/configure
index 1be413a..2cf3835 100755
--- a/configure
+++ b/configure
@@ -6731,6 +6731,7 @@
     echo "TARGET_ABI32=y" >> $config_target_mak
   ;;
   s390x)
+    mttcg=yes
     gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml s390-virt.xml s390-gs.xml"
   ;;
   tilegx)