Add inplace hardswish xnnpack op (#56715)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56715
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55801
Refactor to add inplace version of xnnpack hardswish op
Test Plan: buck test //xplat/caffe2:pt_xnnpack_test
Reviewed By: kimishpatel
Differential Revision: D27712305
fbshipit-source-id: ed1dba22b026251f891fe7b88fbaa9a42985ef2c
