[LLM:Bugfix] Fix LLM build when vision/audio support is disabled

[wangzhaode]

Automated sync from the internal MNN development repository.

• Pending commits: 1
• Head branch: sync/ali-to-github
• Commit authors are preserved from the source commits.

Commits

• 1de1f232dd [LLM:Bugfix] Fix LLM build when vision/audio support is disabled — jingbang.yjb jingbang.yjb@alibaba-inc.com

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