vela: Remove unused serialisation params

 - Removed unused nng parameter

Signed-off-by: Tim Hall <tim.hall@arm.com>
Change-Id: I0bb2eb101a84ea8022c8eb7bcbd86d617e933510
diff --git a/ethosu/vela/compiler_driver.py b/ethosu/vela/compiler_driver.py
index 26d350e..e2c71ac 100644
--- a/ethosu/vela/compiler_driver.py
+++ b/ethosu/vela/compiler_driver.py
@@ -292,10 +292,10 @@
             nng, sg, arch, options.verbose_register_command_stream
         )
         scratch_tens, scratch_fast_tens, flash_tens = npu_serialisation.serialise_npu_subgraph_into_tensors(
-            nng, sg, arch, scratch_tens, scratch_fast_tens, flash_tens
+            sg, arch, scratch_tens, scratch_fast_tens, flash_tens
         )
 
-    npu_serialisation.rewrite_npu_call_ops(nng, root_sg, arch)
+    npu_serialisation.rewrite_npu_call_ops(root_sg, arch)
 
     # Set Scratch and Fast_scratch Tensor size
     if scratch_tens is not None: