NPU adaption for FLUX

[leisuzz]

What does this PR do?

Added Flash Attention for FLUX
Fixed issue in Flux Controlnet when using enable flash attention

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline?
• Did you read our philosophy doc (important for complex PRs)?
• Was this discussed/approved via a GitHub issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

[leisuzz]

@sayakpaul Please take a look at this Flux adaption. Thank you!

[sayakpaul]

Changes to the training script look good to me. Off to @yiyixuxu for the other changes.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[yiyixuxu]

let's keep the default logic simple i.e. remove the changes from this file
you can use NPU with set_attn_processor, no?

[leisuzz]

@yiyixuxu In the attention processor, it has NPU FA, but only with AttnProcessorNPU. Or do you want me to add a function in attention_processor.py to change the processor there? I think right now the selection is only in the init, so it shouldn't be any logic changes. Please let me know what you think so that I can modify based on that. Thanks

In the attention processor, it has NPU FA, but only with AttnProcessorNPU. Or do you want me to add a function in attention_processor.py to change the processor there? I think right now the selection is only in the init, so it shouldn't be any logic changes. Please let me know what you think so that I can modify based on that. Thanks