MLBEDSW-3499: Support for PAD operator

Replaces the PAD operator by hardware padding when possible.

Change-Id: I9dce0885e51a4a73715824d7368637222e39b2b3
Signed-off-by: Louis Verhaard <louis.verhaard@arm.com>
diff --git a/ethosu/vela/test/testutil.py b/ethosu/vela/test/testutil.py
index c345950..96aeb7e 100644
--- a/ethosu/vela/test/testutil.py
+++ b/ethosu/vela/test/testutil.py
@@ -115,8 +115,9 @@
 
 def create_op(op_type, inputs, output, attrs=None):
     op = Operation(op_type, output.name + "_op")
-    op.inputs = inputs
-    op.outputs = [output]
+    for input in inputs:
+        op.add_input_tensor(input)
+    op.set_output_tensor(output)
     if attrs is not None:
         op.attrs = attrs
     op.set_ifm_ofm_shapes()