[quant][ao_migration] `torch.nn.qat` → `torch.ao.nn.qat` (#78716)
Context: In order to avoid the cluttering of the `torch.nn` namespace
the quantized modules namespace is moved to `torch.ao.nn`.
The list of the `nn.quantized` files that are being migrated:
- [X] `torch.nn.quantized` → `torch.ao.nn.quantized`
- [X] `torch.nn.quantized.functional` → `torch.ao.nn.quantized.functional`
- [X] `torch.nn.quantized.modules` → `torch.ao.nn.quantized.modules`
- [X] `torch.nn.quantized.dynamic` → `torch.ao.nn.quantized.dynamic`
- [X] `torch.nn.quantized._reference` → `torch.ao.nn.quantized._reference`
- [X] `torch.nn.quantizable` → `torch.ao.nn.quantizable`
- [X] [Current PR] `torch.nn.qat` → `torch.ao.nn.qat`
- [X] `torch.nn.qat.modules` → `torch.ao.nn.qat.modules`
- [X] `torch.nn.qat.dynamic` → `torch.ao.nn.qat.dynamic`
- [ ] `torch.nn.intrinsic` → `torch.ao.nn.intrinsic`
- [ ] `torch.nn.intrinsic.modules` → `torch.ao.nn.intrinsic.modules`
- [ ] `torch.nn.intrinsic.qat` → `torch.ao.nn.intrinsic.qat`
- [ ] `torch.nn.intrinsic.quantized` → `torch.ao.nn.intrinsic.quantized`
- [ ] `torch.nn.intrinsic.quantized.modules` → `torch.ao.nn.intrinsic.quantized.modules`
- [ ] `torch.nn.intrinsic.quantized.dynamic` → `torch.ao.nn.intrinsic.quantized.dynamic`
Majority of the files are just moved to the new location.
However, specific files need to be double checked:
- None
Differential Revision: [D36861197](https://our.internmc.facebook.com/intern/diff/D36861197/)
**NOTE FOR REVIEWERS**: This PR has internal Facebook specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D36861197/)!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78716
Approved by: https://github.com/jerryzh168
