Remove hip device sync in miopen Conv implementation (#21791)
Summary:
xw285cornell bddppq
Note there are other optimizations coming.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21791
Differential Revision: D15829238
Pulled By: bddppq
fbshipit-source-id: 66c62c646f315d65b4e432ca20890faded843db4
