[docs] Audio task guides fixes
Related to https://github.com/huggingface/transformers/issues/23188 and https://github.com/huggingface/transformers/issues/23222

In the guide examples, only `feature_extractor` is passed to `Trainer`, so that's the only part of the processor that gets pushed to Hub. This PR fixes the docs to pass `processor` to Trainer as the `tokenizer` parameter, so both `feature_extractor` and `tokenizer` are saved. 
The behavior is confirmed with the ASR task guide example. We may also need to fix the example scripts. I'll look into it, and if a fix is needed, I'll create a separate PR. 
_The documentation is not available anymore as the PR was closed or merged._