[kernel] add AscendC op: lightning_indexer and sparse_flash_attention

[MingYang119]

What this PR does / why we need it?

Provide high-performance AscendC operators lightning_indexer and sparse_flash_attention to boost the execution performance of the DeepSeek v3.2 model. Meanwhile, adapt the two AscendC operators to vllm-ascend framework.

Does this PR introduce any user-facing change?

No (only underlying operator optimizations, with no user-facing changes)

How was this patch tested?

• vLLM version: v0.11.2
• vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.2

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[github-actions]

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[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.