rm router logits Improve TTOP 3ms (#1407)

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

The previous code is
router_logits, _ = self.gate(hidden_states)
hidden_states = get_dp_group().all_gather(hidden_states, 0)
router_logits = get_dp_group().all_gather(router_logits, 0)
I want to change the two all_gathers to one, reduce one all_gather
communication, and make it
hidden_states = get_dp_group().all_gather(hidden_states, 0)
router_logits, _ = self.gate(hidden_states)

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

### How was this patch tested?
bash examples/run_dp_attention_etp16.sh
bash examples/run_dp_attention_etp16_benmark.sh

gsm8k accuracy verification
<img width="1809" alt="截屏2025-06-24 21 53 24"
src="https://github.com/user-attachments/assets/47eace3b-a86b-41b4-9de8-773f57fea33b"
/>



- vLLM version: v0.9.2
- vLLM main:
77f77a951e

---------

Signed-off-by: ttanzhiqiang <389825161@qq.com>

vllm_ascend/models/deepseek_v2.py

@@ -367,6 +367,7 @@ class CustomDeepseekV2MoE(nn.Module):
         self.ep_group = get_ep_group()
 
         self.params_dtype = torch.get_default_dtype()
+        self.rm_router_logits = self.experts.rm_router_logits
 
     def forward(self,
                 hidden_states: torch.Tensor,
@@ -389,7 +390,9 @@ class CustomDeepseekV2MoE(nn.Module):
                 is_prefill = is_prefill or attn_metadata.with_prefill_across_dp
 
         # router_logits: (num_tokens, n_experts)
-        router_logits, _ = self.gate(hidden_states)
+        router_logits = None
+        if not self.rm_router_logits:
+            router_logits, _ = self.gate(hidden_states)
 
         experts_hidden_states = self.experts(
             hidden_states=hidden_states,
@@ -398,6 +401,7 @@ class CustomDeepseekV2MoE(nn.Module):
             top_k=CustomDeepseekV2MoE.top_k,
             enable_force_load_balance=enable_force_load_balance,
             shared_experts=self.shared_experts,
+            gate=self.gate,
             replace_allreduce=replace_allreduce)
 
         hidden_states = (