Move specific quantizer related things outside of main quant code base

Summary:
X-link: pytorch/pytorch#107259

Currently in quantizer/quantize_pt2e we import things from specific quantizers (XNNPACKQuantizer, QuantizationConfig) etc.
this PR removes them so it's clearer that they are not part of the core quantization code base

This PR also removed get_supported_operators from main Quantizer since we haven't seen a clear need for this API

Reviewed By: andrewor14

Differential Revision: D48340367

fbshipit-source-id: 368cca59c13b36049f33a8b1ca7842476daf72c5

Author: jerryzh168

backends/xnnpack/test/TARGETS

@@ -22,6 +22,7 @@ python_unittest(
         "//executorch/bundled_program:core",
         "//executorch/bundled_program/serialize:lib",
         "//executorch/exir:lib",
+        "//executorch/exir:tracer",
         "//executorch/exir/backend:backend_api",
         "//executorch/exir/passes:spec_prop_pass",
         "//executorch/exir/serialize:lib",
@@ -51,6 +52,7 @@ python_unittest(
         "//executorch/bundled_program:core",
         "//executorch/bundled_program/serialize:lib",
         "//executorch/exir:lib",
+        "//executorch/exir:tracer",
         "//executorch/exir/backend:backend_api",
         "//executorch/exir/dialects:lib",
         "//executorch/exir/passes:spec_prop_pass",
@@ -81,6 +83,7 @@ python_unittest(
         "//executorch/bundled_program:core",
         "//executorch/bundled_program/serialize:lib",
         "//executorch/exir:lib",
+        "//executorch/exir:tracer",
         "//executorch/exir/backend:backend_api",
         "//executorch/exir/passes:spec_prop_pass",
         "//executorch/exir/serialize:lib",

backends/xnnpack/test/test_xnnpack_utils.py

@@ -69,10 +69,9 @@
     prepare_fx,
 )
 
-from torch.ao.quantization.quantize_pt2e import (
-    convert_pt2e,
+from torch.ao.quantization.quantize_pt2e import convert_pt2e, prepare_pt2e
+from torch.ao.quantization.quantizer.xnnpack_quantizer import (
     get_symmetric_quantization_config,
-    prepare_pt2e,
     XNNPACKQuantizer,
 )
 

backends/xnnpack/test/tester/tester.py

@@ -47,11 +47,12 @@
     prepare_fx,
 )
 from torch.ao.quantization.quantize_pt2e import convert_pt2e, prepare_pt2e
-from torch.ao.quantization.quantizer import XNNPACKQuantizer
-from torch.ao.quantization.quantizer.quantizer import QuantizationConfig, Quantizer
+from torch.ao.quantization.quantizer.quantizer import Quantizer
 from torch.ao.quantization.quantizer.xnnpack_quantizer import (
     get_symmetric_quantization_config,
+    XNNPACKQuantizer,
 )
+from torch.ao.quantization.quantizer.xnnpack_quantizer_utils import QuantizationConfig
 from torch.testing import FileCheck
 from torch.utils._pytree import tree_flatten
 

exir/tests/test_quantization.py

@@ -19,9 +19,9 @@
 from torch.ao.quantization.quantize_fx import convert_to_reference_fx, prepare_fx
 from torch.ao.quantization.quantize_pt2e import convert_pt2e, prepare_pt2e
 
-from torch.ao.quantization.quantizer import XNNPACKQuantizer
 from torch.ao.quantization.quantizer.xnnpack_quantizer import (
     get_symmetric_quantization_config,
+    XNNPACKQuantizer,
 )
 from torch.testing import FileCheck
 from torch.testing._internal.common_quantization import skipIfNoQNNPACK