[Fix doc examples] Add missing from_pretrained (#15044)
* fix doc example - ValueError: Parameter config should be an instance of class `PretrainedConfig`
* Update src/transformers/models/segformer/modeling_segformer.py
Co-authored-by: NielsRogge <48327001+NielsRogge@users.noreply.github.com>
* update
Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>
Co-authored-by: NielsRogge <48327001+NielsRogge@users.noreply.github.com>