Add typing annotations for torch.nn.quantized.dynamic.modules.rnn (#43186)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/43185
xref: [gh-43072](https://github.com/pytorch/pytorch/issues/43072)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43186
Reviewed By: ezyang
Differential Revision: D23441259
Pulled By: malfet
fbshipit-source-id: 80265ae7f3a70f0087e620969dbd4aa8ca17c317
