[MM][Bugfix] Update hf_config to hf_text_config (#5319)

### What this PR does / why we need it?

Following https://github.com/vllm-project/vllm-ascend/pull/5205, update
`hf_config` to `hf_text_config`.

Find more details at
https://github.com/vllm-project/vllm-ascend/pull/5205#issuecomment-3675417534
and
https://github.com/vllm-project/vllm-ascend/pull/5205#issuecomment-3677920872.

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

### How was this patch tested?

- vLLM version: release/v0.13.0
- vLLM main:
5fbfa8d9ef

Signed-off-by: shen-shanshan <467638484@qq.com>

vllm_ascend/ops/linear_op.py

@@ -697,7 +697,7 @@ def is_moe_layer(prefix: str) -> bool:
     def get_moe_params():
         from vllm.config import get_current_vllm_config
         vllm_config = get_current_vllm_config()
-        config = vllm_config.model_config.hf_config
+        config = vllm_config.model_config.hf_text_config
         n_routed_experts = getattr(config, 'n_routed_experts', 0)
         first_k_dense_replace = getattr(config, 'first_k_dense_replace',
                                         float('inf'))