[Feature]: Integrate AITER MLA V1 from Upstream

[tjtanaa]

🚀 The feature, motivation and pitch

After syncing with ROCm/vllm main, cherry pick the changes from upstream to support AITER MLA Engine V1.

Prepare the command to run

VLLM_ATTENTION_BACKEND=ROCM_AITER_MLA VLLM_USE_V1=1 VLLM_ROCM_USE_AITER=1 vllm serve /amdhome/models/DeepSeek-R1 --trust-remote-code -tp 8 --max-model-len 32768 --block-size 1 --no-enable-prefix-caching --max-num-batched-tokens 32768 --max-num-seqs 1024

Suggest a few configurations for the testing team to benchmark.

Alternatives

No response

Additional context

No response

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