replace kernel implementation using CK tile-programming performant kernels

[carlushuang]

We are planning to replace the underneath kernel implementation with the newly developed CK tile-programming fmha kernel. The performance is much better for MI200/MI300, especially for MI300 cases. After this is done, the current implementation in main branch will be deprecated.

• fwd integration with hdim=64/128, support mask, varlen, different kernels for padding case.
• fwd extend to other hdims
• dropout support
• bwd integration (to be planed)

[sabreshao]

@carlushuang Our top priority ask on FA should be enabling E2E training for GPT3/LLAMA2/Qwen/MPT first.
Are you proposing to start integration based on current ROCM FA or base on latest upstream FA?