Update batch size limitation of dsv3_router_gemm kernel to 16 (#8051)

Author: Fridge003

python/sglang/srt/models/deepseek_v2.py

@@ -252,8 +252,7 @@ def forward(self, hidden_states):
         # NOTE: For some unknown reason, router_gemm seems degrade accept length.
         if (
             _is_cuda
-            and not self.is_nextn
-            and hidden_states.shape[0] < 4
+            and hidden_states.shape[0] <= 16
             and hidden_states.shape[1] == 7168
             and self.weight.shape[0] == 256
             and _device_sm >= 90