fix bug auto loading llamatokenizer
Author: vxfla
Pull request: yes

# What does this PR do?
Huggingface decapoda-research/llama-7b-hf config decide the name of tokenizer LLaMATokenizer, while in transformers it is LlamaTokenizer.
Unify the name as LLaMATokenizer, so that we can use AutoTokenizer to load llama tokenizer.
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Fixes # (issue)


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Models:

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Library:

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Comments:
Lol no, but nice try. Maybe decapoda-research/llama-7b-hf should merge one of the multiple PRs they received that fixes the tokenizer on their side.

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