adapters: support bulk connections

src/main/scala/tilelink/Fragmenter.scala

@@ -292,7 +292,7 @@ object TLFragmenter
   // applied to the TL source node; y.node := TLFragmenter(x.node, 256, 4)
   def apply(minSize: Int, maxSize: Int, alwaysMin: Boolean = false, earlyAck: Boolean = false)(x: TLOutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): TLOutwardNode = {
     val fragmenter = LazyModule(new TLFragmenter(minSize, maxSize, alwaysMin, earlyAck))
-    fragmenter.node := x
+    fragmenter.node :=? x
     fragmenter.node
   }
 }