[Fix] Modify tile-based method of supporting large VPT in moe_fused_gate kernel

[ttaohe]

MoE Fused Gate: add tiled path and static specializations for large VPT (64/384), unify switch-case dispatch, and provide multi-dtype benchmarking.

• Added a tiled implementation for large VPT and two static specializations for THREADS_PER_ROW=1: (num_experts=64, group=1) and (num_experts=384, group=1). These are exposed via consistent switch-case dispatch using LAUNCH_MOE_GATE_TILED_CONFIG.
• Kept existing template fast paths for small VPT (e.g., 128/256), and route all other large-VPT cases to the generic tiled kernel.
• Refactored tiled declarations/macros into moe_fused_gate_tiled.h to keep moe_fused_gate.cu clean.
• Added a benchmark (bf16/fp16/fp32) comparing Original (eager, compile-static, compile-dynamic) vs SGL Kernel on representative large-VPT configs.

Results of kimi-vl and kimi-k2

Benchmmmu result of kimi-vl