Enable AttnFuncWithCPAndKVP2P to support mla

[SuperCB]

Description

The function AttnFuncWithCPAndKVP2Pdo not support mla（Multi-latent attention）, because it concats K and V into a single tensor for communication, different head_dim of K and V prevents us from doing the concat.I attempted to pad v to align its head dimension with that of k, thereby enabling support for mla with minimal modifications. issue

Type of change

• [ ] Documentation change (change only to the documentation, either a fix or a new content)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Infra/Build change
• [ ] Code refactoring

Changes

Please list the changes introduced in this PR:

Checklist:

• [x] I have read and followed the contributing guidelines
• [ ] The functionality is complete
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes