[Quant] Add dynamic QAT Linear module (#67325)
Summary:
**Summary:** This commit adds the `torch.nn.qat.dynamic.modules.Linear`
module, the dynamic counterpart to `torch.nn.qat.modules.Linear`.
Functionally these are very similar, except the dynamic version
expects a memoryless observer and is converted into a dynamically
quantized module before inference.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67325
Test Plan:
`python3 test/test_quantization.py TestQuantizationAwareTraining.test_dynamic_qat_linear`
**Reviewers:** Charles David Hernandez, Jerry Zhang
**Subscribers:** Charles David Hernandez, Supriya Rao, Yining Lu
**Tasks:** 99696812
**Tags:** pytorch
Reviewed By: malfet, jerryzh168
Differential Revision: D32178739
Pulled By: andrewor14
fbshipit-source-id: 5051bdd7e06071a011e4e7d9cc7769db8d38fd73
