tdt-loss: add TDT loss kernel

[ebezzam]

What does this PR do?

Goal of this PR is to add a kernel that has been drafted by @eustlb for the recently merged Parakeet TDT.

It's a very rough draft with a lot of Claude help as it's my first time working with kernels 😅

TODO

• @eustlb: I guess you had a .cu file to create the .so file here? From what I understand, we will need to add it here.
• Add the kernel to https://huggingface.co/kernels-community
• Update the tests
• Double-check with this checklist

Perhaps we can see how other kernels used in Transformers were integrated. As the kernel is for a function, maybe rotary_pos_emb is a good example? Here are the files in this repo.

Here is a draft PR for adding/using this kernel in Transformers: huggingface/transformers#46048

cc @vasqu

[github-actions]

Hi @ebezzam, thanks for your interest in contributing!

This project requires that pull request authors are vouched, and you are not in the list of vouched users.

This PR will be closed automatically. See https://github.com/huggingface/kernels-community/blob/main/CONTRIBUTING.md for more details.