[Bugfix] Fix num_hidden_layers when Qwen2-Audio 7B (#1803)

### What this PR does / why we need it?
Fix num_hidden_layers when Qwen2-Audio 7B and #1760 ：
```
INFO 07-15 04:38:53 [platform.py:174] PIECEWISE compilation enabled on NPU. use_inductor not supported - using only ACL Graph mode
Traceback (most recent call last):
  File "/workspace/test1.py", line 58, in <module>
    main(audio_count)
  File "/workspace/test1.py", line 38, in main
    llm = LLM(model="Qwen/Qwen2-Audio-7B-Instruct",
  File "/vllm-workspace/vllm/vllm/entrypoints/llm.py", line 271, in __init__
    self.llm_engine = LLMEngine.from_engine_args(
  File "/vllm-workspace/vllm/vllm/engine/llm_engine.py", line 494, in from_engine_args
    vllm_config = engine_args.create_engine_config(usage_context)
  File "/vllm-workspace/vllm/vllm/engine/arg_utils.py", line 1286, in create_engine_config
    config = VllmConfig(
  File "/usr/local/python3.10.17/lib/python3.10/site-packages/pydantic/_internal/_dataclasses.py", line 123, in __init__
    s.__pydantic_validator__.validate_python(ArgsKwargs(args, kwargs), self_instance=s)
  File "/vllm-workspace/vllm/vllm/config.py", line 4624, in __post_init__
    current_platform.check_and_update_config(self)
  File "/vllm-workspace/vllm-ascend/vllm_ascend/platform.py", line 180, in check_and_update_config
    update_aclgraph_sizes(vllm_config)
  File "/vllm-workspace/vllm-ascend/vllm_ascend/utils.py", line 307, in update_aclgraph_sizes
    num_hidden_layers = vllm_config.model_config.hf_config.num_hidden_layers
  File "/usr/local/python3.10.17/lib/python3.10/site-packages/transformers/configuration_utils.py", line 211, in __getattribute__
    return super().__getattribute__(key)
AttributeError: 'Qwen2AudioConfig' object has no attribute 'num_hidden_layers'
```

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

Closes: https://github.com/vllm-project/vllm-ascend/issues/1780
https://github.com/vllm-project/vllm-ascend/issues/1760
https://github.com/vllm-project/vllm-ascend/issues/1276
https://github.com/vllm-project/vllm-ascend/issues/359

- vLLM version: v0.10.0
- vLLM main:
7728dd77bb

Signed-off-by: hfadzxy <starmoon_zhang@163.com>

docs/source/tutorials/single_npu_audio.md

@@ -90,8 +90,7 @@ def main(audio_count: int):
     llm = LLM(model="Qwen/Qwen2-Audio-7B-Instruct",
               max_model_len=4096,
               max_num_seqs=5,
-              limit_mm_per_prompt={"audio": audio_count},
-              enforce_eager=True)
+              limit_mm_per_prompt={"audio": audio_count})
 
     inputs = prepare_inputs(audio_count)
 

docs/source/tutorials/single_npu_multimodal.md

@@ -57,7 +57,6 @@ llm = LLM(
     model=MODEL_PATH,
     max_model_len=16384,
     limit_mm_per_prompt={"image": 10},
-    enforce_eager=True,
 )
 
 sampling_params = SamplingParams(
@@ -146,8 +145,7 @@ docker run --rm \
 vllm serve Qwen/Qwen2.5-VL-7B-Instruct \
 --dtype bfloat16 \
 --max_model_len 16384 \
---max-num-batched-tokens 16384 \
---enforce-eager
+--max-num-batched-tokens 16384 
 ```
 
 :::{note}