configure.ac: fix build on GNU/kFreeBSD

Based on existing patch from Debian package.

Debian bug: http://bugs.debian.org/524690

Reviewed-by: Andreas Boll <andreas.boll.dev@gmail.com>

configure.ac

@@ -970,7 +970,7 @@ if test "x$enable_dri" = xyes; then
             ;;
         esac
         ;;
-    freebsd* | dragonfly* | *netbsd* | openbsd*)
+    *freebsd* | dragonfly* | *netbsd* | openbsd*)
         DEFINES="$DEFINES -DHAVE_PTHREAD -DUSE_EXTERNAL_DXTN_LIB=1"
         DEFINES="$DEFINES -DHAVE_ALIAS"