[Tunne] Retune kimi k2 moe configs

[lalala-sh]

Motivation

Retune Kimi configs: Add the third expert group with inter_dim=385, topk=9 to provide full MoE configuration coverage for the Kimik2 model.
Fix fallback config overwrite bug in incremental tuning: result_to_csv incorrectly removes all existing flydsl_fallback rows from the CSV when writing new shape results, causing previously tuned shapes to lose their non-flydsl fallback configurations. This means those shapes cannot fall back to CK kernels when flydsl is unavailable, breaking compatibility.

Technical Details

Test Plan

Test Result

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

[github-actions]

🏷️ CI Guide

Runs automatically on every PR:

• ✅ Pre-checks (submodule verification, code formatting)
• ✅ Aiter op tests (gfx942 + gfx950)
• ✅ Triton tests (only when aiter/ops/triton/** or related paths are changed)

Extended tests (opt-in via labels):

Label	Tests
ci:triton-355	Run Triton tests on MI355 in addition to MI325
ci:sglang	SGLang integration tests
ci:atom	ATOM benchmark (DeepSeek-R1 + GPT-OSS)
ci:vllm	vLLM benchmark
ci:all	All of the above

Add labels via the sidebar or gh pr edit 2625 --add-label <label>