[ROCm] Enable BFloat16 for pow, exp, erf ops on ROCm (#40236)
Summary:
Enable ops used in BERT which were missed in one of my earlier PRs.
ezyang jeffdaily
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40236
Differential Revision: D22143965
Pulled By: ezyang
fbshipit-source-id: 5464ed021687fec1485e1c061e5a7aba71687fc4
