Add nn.qat.Linear (#22714)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22714
We need this module for add fake_quant for weight
Reviewed By: zafartahirov
Differential Revision: D16193585
fbshipit-source-id: ed6c04ecf574ca1fe1dcded22c225da05976f7a3
