[ROCm] Enable topk operator for bfloat16 dtype
Support for PR #[59977](https://github.com/pytorch/pytorch/pull/59977) in ROCm
Fixes #[56176](https://github.com/pytorch/pytorch/issues/56176) in ROCm since ROCm 5.0 supports dtype bfloat16 for sorting.
Dependency - PR #[72854](https://github.com/pytorch/pytorch/pull/72854) to be merged before
CC Please review @jithunnair-amd @jeffdaily
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71913
Approved by: https://github.com/jithunnair-amd, https://github.com/osalpekar
