[BE] minor improvement to dist quantization (#67401)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67401
some minor changes to dist quantization, mainly change the namespace and add some notes for future code dedup
ghstack-source-id: 143910067
ghstack-source-id: 143910067
Test Plan: wait for ci
Reviewed By: mrshenli
Differential Revision: D31979269
fbshipit-source-id: 85a2f395e6a3487dd0b9d1fde886eccab106e289
