[Bugfix] Fix DSV3.2 NVFP4

[MatthewBonanni]

Purpose

Fix #33859

Test Plan

Test Result

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @MatthewBonanni.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[gemini-code-assist]

Code Review

This pull request introduces a bugfix for Multi-Head Latent Attention (MLA), likely related to DeepSeek V3.2 models using specific quantization formats. The changes prevent an unnecessary and potentially incorrect view casting of the KV cache when the kv_cache_dtype is fp8_ds_mla. Additionally, a safeguard is added to ensure that FP8 query quantization is only performed if the attention implementation supports it, and this support is explicitly enabled for MLACommonImpl. These changes are correct, well-targeted, and improve the robustness of the code. The fix appears solid.