[MLBEDSW-2787] Remove op.attrs["rescale"] in softmax.py

Added RescaleAdd operation to avoid non-standard attribute
"rescale" for Add operation. Also changed ResizeBilinear
in the same way.

Signed-off-by: Fredrik Svedberg <fredrik.svedberg@arm.com>
Change-Id: I1d286f63890585c06b8a161df1ff77e3f844a4b9
diff --git a/ethosu/vela/operation_util.py b/ethosu/vela/operation_util.py
index a55b954..7015b79 100644
--- a/ethosu/vela/operation_util.py
+++ b/ethosu/vela/operation_util.py
@@ -16,6 +16,7 @@
 # Description:
 # Utility functions for creating Network Operations.
 from typing import Optional
+from typing import Tuple
 
 from .data_type import DataType
 from .high_level_command_to_npu_op import ifm_ifm2_correct_order
@@ -98,6 +99,21 @@
     return create_binary_elementwise(Op.Add, name, ifm, ifm2, quantization, activation, dtype, attrs)
 
 
+def create_rescale_add(
+    name: str,
+    ifm: Tensor,
+    ifm2: Tensor,
+    rescale: Tuple[int, int],
+    quantization: QuantizationParameters,
+    activation: Optional[ActivationFunction] = None,
+    dtype: Optional[DataType] = None,
+    attrs: Optional[dict] = None,
+) -> Operation:
+    op = create_binary_elementwise(Op.RescaleAdd, name, ifm, ifm2, quantization, activation, dtype, attrs)
+    op.rescale = rescale
+    return op
+
+
 def create_clz(
     name: str,
     ifm: Tensor,