IBM Granite models support?

```
from ctransformers import AutoModelForCausalLM

llm = AutoModelForCausalLM.from_pretrained("ibm-granite/granite-3.1-2b-instruct", model_type="gpt2")

print(llm("Tell me the difference between thinking in humans and in LLMs."))
```

the above doesn't work. how can I use it?
