Update config.py (#2224)

Needed for layout:

ValueError: Failed to find class QDQLayout in any of the allowed modules: torchao.prototype.quantization, torchao.sparsity.sparse_api, torchao.prototype.mx_formats, torchao.quantization

Author: jerryzh168

torchao/core/config.py

@@ -176,6 +176,7 @@ def config_to_dict(config: AOBaseConfig) -> Dict[str, Any]:
     "torchao.sparsity.sparse_api",
     "torchao.prototype.quantization",
     "torchao.prototype.mx_formats",
+    "torchao.dtypes",
 }