[ROCm] [ROCm 2.10+] enable fp16 dot in Caffe2 backend (#30432)
Summary:
ROCm 2.10 has a hdot implementation, use it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30432
Differential Revision: D20777482
Pulled By: ezyang
fbshipit-source-id: b4826cc399faa08bd83047375283b17bcd2477eb
