[AIX]eigen update fix and test failures fix (#23751)
### Description
Changes in this PR are for:
- Cleanup the patch for Eigen on AIX. Not needed anymore .
- Fix to recent test failures
```
1: [----------] Global test environment tear-down
1: [==========] 4737 tests from 310 test suites ran. (94682 ms total)
1: [ PASSED ] 4733 tests.
1: [ SKIPPED ] 2 tests, listed below:
1: [ SKIPPED ] MatMulFpQ4.MatMul2DSym
1: [ SKIPPED ] MatMulFpQ4.MatMul2DBlkZp
1: [ FAILED ] 2 tests, listed below:
1: [ FAILED ] GraphTransformationTests.MatMulAddFusion_three_input_with_1d
1: [ FAILED ] GraphTransformationTests.MatMulAddFusion_NeedReshape_3D
```
---------
Co-authored-by: Tianlei Wu <tlwu@microsoft.com>
