ROCm: Enable tf32 testing on test_nn (#55)

**Commit:** 70a5f9fa212250a2703c1b6cfdd474fb05269fb5
**Author:** Jagadish Krishnamoorthy (jagadish.krishnamoorthy@amd.com)
**Branch:** develop
**Link:** [View commit](https://github.com/ROCm/pytorch/commit/70a5f9fa212250a2703c1b6cfdd474fb05269fb5)