WIP porting of lite transformer
# What does this PR do?

#19730


@NielsRogge  Needs some help how to go about the conversion script and testing. 

The original model is not in pytorch hub, I has only Google Drive link. In the conversion script should I download and convert ? <|||||>The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_21235). All of your documentation changes will be reflected on that endpoint.<|||||>This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.<|||||>Hi @raghavanone, do you still want to proceed with this PR? If yes, I'll reopen it :) <|||||>@NielsRogge  Yes, Please it keep it open, I want to wrap up UDOP PR beforing wraping this up . 