Migrate crossKernel from THC to ATen (CUDA) (#60039)
Summary:
Ref https://github.com/pytorch/pytorch/issues/24507 (There doesn't seem to be an actual issue for cross)
This also moves the remaining operator functors in `THCTensorMathPointwise.cuh` to `SparseCUDATensorMath.cu` which is the only file using them.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60039
Reviewed By: mrshenli
Differential Revision: D29314638
Pulled By: ngimel
fbshipit-source-id: aa7b57f6e11a933fb44f044e26945bb4a9e3de5f
