Add note on ifdefing based on CUDA_VERSION for ROCm path (#62850)
Summary:
CUDA_VERSION and HIP_VERSION follow very unrelated versioning schemes, so it does not make sense to use CUDA_VERSION to determine the ROCm path. This note explicitly addresses it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62850
Reviewed By: mruberry
Differential Revision: D30547562
Pulled By: malfet
fbshipit-source-id: 02990fa66a88466c2330ab85f446b25b78545150
