Change unpacking of TF mobilebert inputs to use decorator
# What does this PR do?

As part of #16051 this PR changes the unpacking of the inputs of TF mobilebert to use the decorator instead.

## 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/master/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [x] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [x] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/master/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/master/docs#writing-source-documentation).
- [x] Did you write any new necessary tests?

## Who can review?

@Rocketknight1 @gante 

_The documentation is not available anymore as the PR was closed or merged._<|||||>@gante I have run the test and all pass. But when I run `make fixup` in my windows laptop it throws the error `-n was unexpected at this time.
make: *** [Makefile:10: modified_only_fixup] Error 255
` Do you know how to fix it?<|||||>> @gante I have run the test and all pass. But when I run `make fixup` in my windows laptop it throws the error `-n was unexpected at this time. make: *** [Makefile:10: modified_only_fixup] Error 255 ` Do you know how to fix it?

Check our guide [here](https://github.com/huggingface/transformers/blob/master/CONTRIBUTING.md#develop-on-windows) :)<|||||>Thank you :D 