[AMD][MI355X] update model for gpt-oss (#1670)

* Update amd-master.yaml

* Add perf-changelog entry placeholder

Record the GPT-OSS MI355X vLLM model update
(amd/gpt-oss-120b-w-mxfp4-a-fp8 -> openai/gpt-oss-120b).

* Update the changelog

---------

Co-authored-by: ukannika <uma.kannikanti@amd.com>

Author: chunfangamd

.github/configs/amd-master.yaml

@@ -1134,7 +1134,7 @@ gptoss-fp4-mi325x-vllm:
 
 gptoss-fp4-mi355x-vllm:
   image: vllm/vllm-openai-rocm:v0.22.0
-  model: amd/gpt-oss-120b-w-mxfp4-a-fp8
+  model: openai/gpt-oss-120b
   model-prefix: gptoss
   runner: mi355x
   precision: fp4

perf-changelog.yaml

@@ -3487,3 +3487,10 @@
     - "Switch attention backend from FLASHINFER to FLASH_ATTN for the 8k/1k cell of MiniMax-M2.5 FP8 H200 vLLM."
     - "1k/1k cell not changed in this PR: at 1k/1k all three measured configs."
   pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/1668
+
+- config-keys:
+    - gptoss-fp4-mi355x-vllm
+  description:
+    - "Update GPT-OSS model for MI355X vLLM from amd/gpt-oss-120b-w-mxfp4-a-fp8 to openai/gpt-oss-120b"
+  pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/1670
+