Enable torch.backends.quantized typechecks (#44794)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/44793
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44794
Reviewed By: walterddr
Differential Revision: D23734353
Pulled By: malfet
fbshipit-source-id: 491bd7c8f147759715eb296d7537a172685aa066
