Add additional variables without shape
Author: MadhumitaSushil
Pull request: yes

These additional training variables without shape are present in the NVIDIA implementation for training BERT models: https://github.com/NVIDIA/DeepLearningExamples/tree/master/TensorFlow/LanguageModeling/BERT . The conversion works as expected after this change.

# What does this PR do?

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Fixes # (issue)


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Comments:
Hi, thanks for opening a PR!

Could you run `make fixup` at the root of your clone to apply to code quality fixes?

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/master/CONTRIBUTING.md) are likely to be ignored.