[Optimization] merge matmul and add

[BingooYang]

Motivation

性能优化

Modifications

将UnquantizedLinearMethod中的matmul和add用linear替换。
带bias情况基本上有加速，不带bias情况小shape下性能有下降（主要是python层if等调度开销，linear内部实现也是matmul）。

Usage or Command

无

Accuracy Tests

精度保持一致

Checklist

• [ x ] Add at least a tag in the PR title.
  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
  • You can add new tags based on the PR content, but the semantics must be clear.
• [ x ] Format your code, run pre-commit before commit.
• [ x ] Add unit tests. Please write the reason in this PR if no unit tests.
• [ x ] Provide accuracy results.
• [ x ] If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[paddle-bot]

Thanks for your contribution!