[NPU]support fused neighborhood attention for npu (#1034)

## Summary
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this proposed code change. --->
This PR introduces support for Fused Neighborhood Attention (FNA)
optimized specifically for NPU architectures. The implementation focuses
on memory efficiency and hardware affinity to prevent performance
bottlenecks. Key modifications include:

Grid Dimension Refactoring: Adjusted the attention grid to a 1D
structure. This change optimizes thread block mapping and prevents User
Buffer (UB) overflow, ensuring the workload fits within the NPU's local
memory constraints.

NPU-Affinity Softmax: Refactored the Softmax tiling and grid dimensions
to align with NPU compute unit sizes, maximizing throughput and reducing
synchronization overhead.

## Details
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## Details
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should be aware of?
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Hardware Type: NPU（Atlas A2)
## Testing Done
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tested. --->

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Tested passed with
`python benchmark/scripts/benchmark_fused_neighborhood_attention.py `
`pytest -v  test/transformers/test_fused_neighborhood_attention.py`

- [x] run `make test` to ensure correctness
- [x] run `make checkstyle` to ensure code style
- [ ] run `make test-convergence` to ensure convergence

---------

Co-authored-by: lowdy1 <xiahouweidong@gmail.com>

Author: Hailey-Zh

src/liger_kernel/ops/backends/_ascend/ops/__init__.py

@@ -29,6 +29,8 @@
 from liger_kernel.ops.backends._ascend.ops.fused_linear_jsd import LigerFusedLinearJSDFunction
 from liger_kernel.ops.backends._ascend.ops.fused_linear_jsd import fused_linear_jsd_backward
 from liger_kernel.ops.backends._ascend.ops.fused_linear_jsd import fused_linear_jsd_forward
+from liger_kernel.ops.backends._ascend.ops.fused_neighborhood_attention import LigerFusedNeighborhoodAttentionFunction
+from liger_kernel.ops.backends._ascend.ops.fused_neighborhood_attention import fused_neighborhood_attention_forward
 from liger_kernel.ops.backends._ascend.ops.geglu import LigerGELUMulFunction
 from liger_kernel.ops.backends._ascend.ops.geglu import geglu_backward
 from liger_kernel.ops.backends._ascend.ops.geglu import geglu_forward
@@ -136,4 +138,6 @@
     "LigerSparsemaxFunction",
     "sparsemax_forward",
     "sparsemax_backward",
+    "LigerFusedNeighborhoodAttentionFunction",
+    "fused_neighborhood_attention_forward",
 ]