Add back from_transformers for base model (#2288)
* fix
* fix
* support legacy
* Update optimum/modeling_base.py
* fix
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Co-authored-by: IlyasMoutawwakil <moutawwakil.ilyas.tsi@gmail.com>
Co-authored-by: Ilyas Moutawwakil <57442720+IlyasMoutawwakil@users.noreply.github.com>
