[optimize] add two stream norm for qwen3 (#7740)

Co-authored-by: ispobock <ispobaoke@gmail.com>

python/sglang/srt/models/qwen2_moe.py

@@ -291,6 +291,7 @@ class Qwen2MoeDecoderLayer(nn.Module):
         layer_id: int,
         quant_config: Optional[QuantizationConfig] = None,
         prefix: str = "",
+        alt_stream: Optional[torch.cuda.Stream] = None,
     ) -> None:
         super().__init__()
         self.config = config
@@ -393,6 +394,7 @@ class Qwen2MoeModel(nn.Module):
         quant_config: Optional[QuantizationConfig] = None,
         prefix: str = "",
         decoder_layer_type: type[nn.Module] = Qwen2MoeDecoderLayer,
+        alt_stream: Optional[torch.cuda.Stream] = None,
     ) -> None:
         super().__init__()
         self.padding_idx = config.pad_token_id
@@ -418,6 +420,7 @@ class Qwen2MoeModel(nn.Module):
                 config=config,
                 quant_config=quant_config,
                 prefix=prefix,
+                alt_stream=alt_stream,
             ),
             pp_rank=self.pp_group.rank_in_group,
             pp_size=self.pp_group.world_size,