[Perf]Add YaRN custom op (#3355)

### What this PR does / why we need it?
YaRN scaling is used to improve long seq accuracy for models like Qwen3.
In vLLM, YaRN scaling refers to `YaRNScalingRotaryEmbedding` class which
inherits from original `RotaryEmbedding`. Although
`YaRNScalingRotaryEmbedding` does not rewrite the `forward` function of
`RotaryEmbedding` , using YaRN on npu still run into the native
implementation of foward in `RotaryEmbedding`, rather than forward_oot
in vLLM-Ascend. Thus I register another custom op here to enable the oot
implementation for YaRN in vLLM-Ascend, similar to #3151 .

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

---------

Signed-off-by: Angazenn <supperccell@163.com>

vllm_ascend/utils.py

@@ -508,7 +508,8 @@ def register_ascend_customop(vllm_config: Optional[VllmConfig] = None):
                                         AscendQKVParallelLinear,
                                         AscendRowParallelLinear)
     from vllm_ascend.ops.rotary_embedding import (
-        AscendDeepseekScalingRotaryEmbedding, AscendRotaryEmbedding)
+        AscendDeepseekScalingRotaryEmbedding, AscendRotaryEmbedding,
+        AscendYaRNRotaryEmbedding)
     from vllm_ascend.ops.vocab_parallel_embedding import (
         AscendLogitsProcessor, AscendParallelLMHead,
         AscendVocabParallelEmbedding)
@@ -520,6 +521,7 @@ def register_ascend_customop(vllm_config: Optional[VllmConfig] = None):
         "RotaryEmbedding": AscendRotaryEmbedding,
         "ColumnParallelLinear": AscendColumnParallelLinear,
         "RowParallelLinear": AscendRowParallelLinear,
+        "YaRNScalingRotaryEmbedding": AscendYaRNRotaryEmbedding,
         "MergedColumnParallelLinear": AscendMergedColumnParallelLinear,
         "QKVParallelLinear": AscendQKVParallelLinear,
         "DeepseekScalingRotaryEmbedding": AscendDeepseekScalingRotaryEmbedding,