[Bugfix][Model] Fix baichuan model loader for tp

[MengqingCao]

Fix vllm-project/vllm-ascend#934, actually this issue is same on gpu

Fix baichuan model loader for tp. There is a customized lm_head_weight_loader in Baichuan, but it use default weight loader to load weights, this causes the above issue. This pr fix it by taking tensor parallel weight spilt into account.

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[DarkLight1337]

Thanks for fixing!