remove type information from docstrings of quantization functions (#28556)
Summary:
Following from https://github.com/pytorch/pytorch/issues/28479 let's remove the type information from the docstrings of these functions as well, making them valid python signatures matching the other signatures in the docstrings for the torch API.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28556
Differential Revision: D18115641
Pulled By: ezyang
fbshipit-source-id: e4c3d56981b16f5acabe8be7bfbe6ae506972d7f
