Add facebook/MobileLLM-125M

[redpanda1995]

What does this PR do?

Fixes # #43742

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[github-actions]

[For maintainers] Suggested jobs to run (before merge)

run-slow: mobilellm

[vasqu]

Tbh this model is not used by many (1k downloads per month); we have a policy to deprecate low usage models (<10k downloads) so I don't feel good about investing resources into this integration - it should rather fix its remote code 👀