Revert "MLBEDSW-3645 4D class for op ifm/ofm shapes"

This reverts commit bf31d647dc5df47410ee577b12427ddf076d816b.

Reason for revert: <INSERT REASONING HERE>

Change-Id: I7b6c585b7658f94dbaa916c2b6bfe9fb463b8d37
diff --git a/ethosu/vela/test/testutil.py b/ethosu/vela/test/testutil.py
index c345950..63f841b 100644
--- a/ethosu/vela/test/testutil.py
+++ b/ethosu/vela/test/testutil.py
@@ -75,7 +75,7 @@
 
 
 def create_op_with_quant_tensors(
-    op_type, ifm_shape, ofm_shape, weights_shape=None, bias_shape=None, datatype=DataType.uint8, set_ifm_ofm_shapes=True
+    op_type, ifm_shape, ofm_shape, weights_shape=None, bias_shape=None, datatype=DataType.uint8
 ):
     ifm = Tensor(ifm_shape, datatype, "in")
     ifm.quantization = default_quant_params()
@@ -107,9 +107,7 @@
         bias = create_const_tensor("bias", bias_shape, DataType.int32, np.zeros(bias_shape), np.int32, quantization=qp)
         op.add_input_tensor(bias)
 
-    if set_ifm_ofm_shapes:
-        op.set_ifm_ofm_shapes()
-
+    op.set_ifm_ofm_shapes()
     return op