Update QNNPACK (#15561)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15561
- Update QNNPACK submodule to master (API-incompatible)
- Do matching changes in Caffe2 Int8 operators
Reviewed By: dreiss
Differential Revision: D13551322
fbshipit-source-id: 066f9087061167f7d7cfbc1c8f8628dfa93d056e