Arm backend: Backend test serializes and uses EthosUQuant on Ethos-U flows (#14817)

### Summary

Serialize and quantize automaticaly when possible. This make Ethos-U
flows work.

### Test plan
This is runned by the backed suit testing for Ethos-U

Signed-off-by: Zingo Andersen <[email protected]>

Author: zingo

backends/test/suite/flows/arm.py

@@ -3,70 +3,66 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+# Create flows for Arm Backends used to test operator and model suits
 
-from executorch.backends.arm.quantizer import (
-    get_symmetric_quantization_config,
-    TOSAQuantizer,
-)
+from executorch.backends.arm.common.arm_compile_spec import ArmCompileSpec
+from executorch.backends.arm.quantizer import get_symmetric_quantization_config
 from executorch.backends.arm.test import common
 from executorch.backends.arm.test.tester.arm_tester import ArmTester
+from executorch.backends.arm.tosa.compile_spec import TosaCompileSpec
+from executorch.backends.arm.util._factory import create_quantizer
 from executorch.backends.test.suite.flow import TestFlow
 from executorch.backends.xnnpack.test.tester.tester import Quantize
 
 
-def _create_tosa_flow(
+def _create_arm_flow(
     name,
-    compile_spec,
-    quantize: bool = False,
+    compile_spec: ArmCompileSpec,
     symmetric_io_quantization: bool = False,
     per_channel_quantization: bool = True,
 ) -> TestFlow:
 
     def _create_arm_tester(*args, **kwargs) -> ArmTester:
         kwargs["compile_spec"] = compile_spec
+        return ArmTester(*args, **kwargs)
+
+    support_serialize = not isinstance(compile_spec, TosaCompileSpec)
+    quantize = compile_spec.tosa_spec.support_integer()
 
-        return ArmTester(
-            *args,
-            **kwargs,
-        )
+    if quantize is True:
 
-    # Create and configure quantizer to use in the flow
-    def create_quantize_stage() -> Quantize:
-        quantizer = TOSAQuantizer(compile_spec)
-        quantization_config = get_symmetric_quantization_config(
-            is_per_channel=per_channel_quantization
-        )
-        if symmetric_io_quantization:
-            quantizer.set_io(quantization_config)
-        return Quantize(quantizer, quantization_config)
+        def create_quantize_stage() -> Quantize:
+            quantizer = create_quantizer(compile_spec)
+            quantization_config = get_symmetric_quantization_config(
+                is_per_channel=per_channel_quantization
+            )
+            if symmetric_io_quantization:
+                quantizer.set_io(quantization_config)
+            return Quantize(quantizer, quantization_config)
 
     return TestFlow(
         name,
         backend="arm",
         tester_factory=_create_arm_tester,
-        supports_serialize=False,
+        supports_serialize=support_serialize,
         quantize=quantize,
-        quantize_stage_factory=create_quantize_stage if quantize else None,
+        quantize_stage_factory=(create_quantize_stage if quantize is True else False),
     )
 
 
-ARM_TOSA_FP_FLOW = _create_tosa_flow(
-    "arm_tosa_fp", common.get_tosa_compile_spec(tosa_spec="TOSA-1.0+FP")
+ARM_TOSA_FP_FLOW = _create_arm_flow(
+    "arm_tosa_fp",
+    common.get_tosa_compile_spec(tosa_spec="TOSA-1.0+FP"),
 )
-ARM_TOSA_INT_FLOW = _create_tosa_flow(
+ARM_TOSA_INT_FLOW = _create_arm_flow(
     "arm_tosa_int",
     common.get_tosa_compile_spec(tosa_spec="TOSA-1.0+INT"),
-    quantize=True,
 )
-
-ARM_ETHOS_U55_FLOW = _create_tosa_flow(
+ARM_ETHOS_U55_FLOW = _create_arm_flow(
     "arm_ethos_u55",
     common.get_u55_compile_spec(),
-    quantize=True,
 )
-
-ARM_ETHOS_U85_FLOW = _create_tosa_flow(
+ARM_ETHOS_U85_FLOW = _create_arm_flow(
     "arm_ethos_u85",
     common.get_u85_compile_spec(),
-    quantize=True,
 )