Rename to reflect framework pattern AutoModelXxx -> TFAutoModelXxx
# What does this PR do?

Fixes a small bug to make sure a TFAutoModel class keeps the TF naming pattern when being updated with `auto_class_update`.

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? 
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?

## Who can review?

Anyone in the community is free to review the PR once the tests have passed. 
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thank you for the fix, @amyeroberts 🚀 <|||||>@amyeroberts You can now merge the PR (`Squash and merge` button)