diplomacy: change API to auto-create node bundles => cross-module refs

src/main/scala/tilelink/ToAXI4.scala

@@ -53,12 +53,7 @@ class TLToAXI4(val beatBytes: Int, val combinational: Boolean = true, val adapte
   val node = TLToAXI4Node(beatBytes, stripBits)
 
   lazy val module = new LazyModuleImp(this) {
-    val io = new Bundle {
-      val in = node.bundleIn
-      val out = node.bundleOut
-    }
-
-    ((io.in zip io.out) zip (node.edgesIn zip node.edgesOut)) foreach { case ((in, out), (edgeIn, edgeOut)) =>
+    (node.in zip node.out) foreach { case ((in, edgeIn), (out, edgeOut)) =>
       val slaves  = edgeOut.slave.slaves
 
       // All pairs of slaves must promise that they will never interleave data