Allow torchao quantization in SiglipMLP

[jerryzh168]

Summary:
SiglipMLP is not quantized by default, so when we try to load a torchao quantized model it doesn't work because the mlps are not quantized, this PR enables quantization when we are loading a torchao quantized checkpoint.

Depends on #14231

Test Plan:
python benchmarks/benchmark_latency.py --input-len 256 --output-len 256 --model jerryzh168/gemma3-4b-it-float8dq --batch-size 1

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[jeejeelee]

Thanks, please address the CI failure.

[jeejeelee]

Thank you, we can merge first