add dcgm guidance for sync with upstream (#1284)
Summary:
Add a guidance for sync up DCGM APIs with upstream
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1284
Reviewed By: xuzhao9
Differential Revision: D41081214
Pulled By: FindHao
fbshipit-source-id: 7de75c1e5f2b7daed3ce3e14a708ba6269f523fb
