configure.ac: advertise XCB
diff --git a/configure.ac b/configure.ac
index e48137f..15f6068 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1033,6 +1033,7 @@
 fi
     echo "        DRI driver dir:  $DRI_DRIVER_INSTALL_DIR"
 fi
+echo "        Use XCB:         $enable_xcb"
 
 dnl Libraries
 echo ""