Trainer - deprecate tokenizer for processing_class (#32385)

* Trainer - deprecate tokenizer for processing_class

* Extend chage across Seq2Seq trainer and docs

* Add tests

* Update to FutureWarning and add deprecation version

docs/source/zh/tasks/asr.md

@@ -298,7 +298,7 @@ Wav2Vec2 分词器仅训练了大写字符，因此您需要确保文本与分
 ...     args=training_args,
 ...     train_dataset=encoded_minds["train"],
 ...     eval_dataset=encoded_minds["test"],
-...     tokenizer=processor,
+...     processing_class=processor,
 ...     data_collator=data_collator,
 ...     compute_metrics=compute_metrics,
 ... )
@@ -389,4 +389,4 @@ Wav2Vec2 分词器仅训练了大写字符，因此您需要确保文本与分
 ['I WOUL LIKE O SET UP JOINT ACOUNT WTH Y PARTNER']
 ```
 </pt>
-</frameworkcontent>
+</frameworkcontent>