Refactor qconv_prepack and qconv_unpack to support conv3d (#28481)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28481
Refactor qconv_prepack and qconv_unpack to support conv3d
Test Plan: buck test mode/dev-nosan caffe2/test:quantized -- "Conv"
Reviewed By: dskhudia
Differential Revision: D18023651
fbshipit-source-id: 8cbc9fe68f93bc4b247a4f41423c6d8c30a5ef90
