MLU devices : Checks if mlu is available via an cndev-based check which won't trigger the drivers and leave mlu
Author: huismiling
Pull request: yes

# What does this PR do?

MLU devices : Checks if mlu is available via an cndev-based check which won't trigger the drivers and leave mlu

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Comments:
@ArthurZucker 
Hi, Could you help to merge this PR ?

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_34326). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

> Hey is there any doc regarding `PYTORCH_CNDEV_BASED_MLU_CHECK` anywhere? Or are we just using / creating is for this?

@ArthurZucker 
Hi, Just using / creating `PYTORCH_CNDEV_BASED_MLU_CHECK` is OK.
Like nvml, CNDEV is a cambricon library for MLUs, . It will not affect pytorch but torch_mlu.

`nvml-based` and `cndev-based` check has been used in accelerate. 
https://github.com/huggingface/accelerate/pull/3187

https://github.com/huggingface/accelerate/blob/ba7ab93f5e688466ea56908ea3b056fae2f9a023/src/accelerate/utils/imports.py#L116
```
def is_cuda_available():
    """
    Checks if `cuda` is available via an `nvml-based` check which won't trigger the drivers and leave cuda
    uninitialized.
    """
    with patch_environment(PYTORCH_NVML_BASED_CUDA_CHECK="1"):
        available = torch.cuda.is_available()

    return available
```

https://github.com/huggingface/accelerate/blob/ba7ab93f5e688466ea56908ea3b056fae2f9a023/src/accelerate/utils/imports.py#L322

```
def is_mlu_available(check_device=False):
    """
    Checks if `mlu` is available via an `cndev-based` check which won't trigger the drivers and leave mlu
    uninitialized.
    """
    if importlib.util.find_spec("torch_mlu") is None:
        return False

    import torch_mlu  # noqa: F401

    with patch_environment(PYTORCH_CNDEV_BASED_MLU_CHECK="1"):
        available = torch.mlu.is_available()

    return available
```


@ArthurZucker 
Hi, is this PR okay to merge ? Is there anything else I can help ?

@ArthurZucker 
Hey, Just remind this .