Merge commit '4b476e6a' into release/2.2

* commit '4b476e6a':
  configure: enable PIC on s390(x)
Merged-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -3661,6 +3661,10 @@ case "$arch" in
         check_64bit ppc ppc64 'sizeof(void *) > 4'
         spic=$shared
     ;;
+    s390)
+        check_64bit s390 s390x 'sizeof(void *) > 4'
+        spic=$shared
+    ;;
     sparc)
         check_64bit sparc sparc64 'sizeof(void *) > 4'
         spic=$shared