Fix doc and type hints for "torch.add"; fix deprecated python calls in tests (#33935)
Summary:
This PR fixed documentation for `torch.add` with alpha. It also fixed these deprecated python calls `torch.add` and `torch.addmm` in tests, which may affect performance in *test/test_sparse.py* and *test/test_nn.py*.
cc csarofeen ptrblck
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33935
Differential Revision: D20313320
Pulled By: ngimel
fbshipit-source-id: fb08413d7e244865952e3fc0e1be7f1794ce4e9a
