[Kernel][Moe Configs] llama4 maverick fp8 moe config tp8 on mi325

[zhewenl]

Purpose

AMD CI is using mi325, but the MoE config is not added:

WARNING [fused_moe.py:886] Using default MoE config. Performance might be sub-optimal!
Config file not found at ['/usr/local/lib/python3.12/dist-packages/vllm/model_executor/layers/fused_moe/configs/E=128,N=1024,device_name=AMD_Instinct_MI325X,dtype=fp8_w8a8.json']

This PR adds llama4 MoE config for mi325, which should be identical to mi300 config here: #16847

[gemini-code-assist]

Code Review

This pull request introduces a new configuration file for Fused Mixture-of-Experts (MoE) kernels, specifically for the AMD Instinct MI325X GPU using the fp8_w8a8 data type. The added file, E=128,N=1024,device_name=AMD_Instinct_MI325X,dtype=fp8_w8a8.json, is intended to resolve a CI failure caused by its absence. The configuration is stated to be identical to that of the MI300X, which is a reasonable approach for enabling support on a similar architecture. The file format and naming convention align with the existing structure for kernel configurations. The change appears correct and should resolve the reported issue.

[gemini-code-assist]

Code Review

This pull request adds a new configuration file for the Fused MoE kernel to support the AMD Instinct MI325X GPU with fp8 precision. The change is straightforward and aims to fix a missing configuration warning, which should provide better performance than the default settings. The new configuration file's naming and structure are consistent with the existing implementation. The kernel parameters within the file appear valid. I have not identified any high or critical severity issues in this pull request.

[yeqcharlotte]

how is the config tuned? is it from autotune script or copied from mi300x? cc: @mxz297 @bradleyhd

[zhewenl]

@yeqcharlotte just copied from mi300 since they share a same architecture