hidl-gen: Fix warnings for unused parameters.

Test: `mma` does not have warnings on unused paramters
      on GraphAll.cpp.

Change-Id: Ib4ddd38c34f1de5aef1cdefdfa0539840fb44a8e
diff --git a/Type.cpp b/Type.cpp
index 0b2b715..54f5956 100644
--- a/Type.cpp
+++ b/Type.cpp
@@ -146,6 +146,10 @@
     CHECK(!"Should not be here");
 }
 
+bool Type::useParentInEmitResolveReferencesEmbedded() const {
+    return true;
+}
+
 void Type::emitReaderWriterEmbedded(
         Formatter &,
         size_t,