Add num logits to keep to granite llms
Author: alex-jw-brooks
Pull request: yes

This PR adds support for `num_logits_to_keep` to Granite models. This also allows Granite to be used as the language model for Llava Next models, which assume that this kwarg is part of the underlying LLM's signature. 

As an aside, should this be a requirement for the underlying LLM signature of llava next encapsulating LLMs in general? I'm happy to submit a follow-up PR to only pass it if it's part of the LLM signature if we'd like to add that flexibility 🙂 

For testing -`num_logits_to_keep` is tested under the common tests [here](https://github.com/huggingface/transformers/blob/main/tests/test_modeling_common.py#L4811); I verified that this test now runs for granite models and passes as expected.


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## Who can review?

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@ArthurZucker

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Comments:
It seems this was added as part of https://github.com/huggingface/transformers/pull/35235 - will close this

Sorry for not reviewing earlier and thanks for contributing! 🤗