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

src/main/scala/devices/tilelink/Zero.scala

@@ -24,12 +24,7 @@ class TLZero(address: AddressSet, resources: Seq[Resource], executable: Boolean
     minLatency = 1))) // no bypass needed for this device
 
   lazy val module = new LazyModuleImp(this) {
-    val io = new Bundle {
-      val in = node.bundleIn
-    }
-
-    val in = io.in(0)
-    val edge = node.edgesIn(0)
+    val (in, edge) = node.in(0)
 
     val a = Queue(in.a, 2)
     val hasData = edge.hasData(a.bits)