Add support for IBM Granite 3.x models

[frreiss]

Motivation

This PR adds support for inference on non-MoE IBM Granite 3.x models (see https://huggingface.co/collections/ibm-granite/granite-30-language-models-66fdb59bbb54785c3512114f).

Granite 3.0's architecture is similar to that of Llama 2 and 3, but with additional multiplier parameters for improved numerical stability through Maximal Update Parameterization.

Modifications

• Added new model type for Granite models
• Backported change to LogitsProcessor from vLLM 0.4. This change add an optional logits multiplier parameter. Granite models use this multiplier to implement Maximal Update Parameterization.
• Added chat template for granite-3-instruct family
• Added 2b parameter Granite model to regression suite

Checklist

• Format your code according to the Contributor Guide.
• Add unit tests as outlined in the Contributor Guide.
• Update documentation as needed, including docstrings or example tutorials.

[merrymercy]

Thanks for the contribution. It is merged!