[CK_TILE] FMHA BWD supports atomic16

[shay-li77]

Proposed changes

ck fa bwd supports atomic b16 for block_fmha_bwd_dq_dk_dv_pipeline_kr_ktr_vr_iglp and block_fmha_bwd_dq_dk_dv_pipeline_kr_ktr_vr pipeline.

Checklist

Please put an x into the boxes that apply. You can also fill these out after creating the PR. If you're not sure, please don't hesitate to ask.

• [x] I have added tests relevant to the introduced functionality, and the unit tests are passing locally
• [x] I have added the test to REGRESSION_TESTS list defined at the top of CMakeLists.txt in tests/CMakeLists.txt, IF the test takes more than 30 seconds to run.
• [x] I have added inline documentation which enables the maintainers with understanding the motivation
• [x] I have removed the stale documentation which is no longer relevant after this pull request
• [x] (If this change is user-facing) I have added release notes which provide the end users with a brief summary of the improvement from this pull request
• [x] I have run clang-format on all changed files
• [x] Any dependent changes have been merged

Discussion

If this is a relatively large or complex change, feel free to start a discussion by explaining why you chose the solution you did and what alternatives you considered

[illsilin]

Please resolve merge conflicts!

[cgmillette]

@shay-li77 Marked this PR as stale. If you have not addressed the reviews in 2 weeks, we will move to close. Thank you!

[cgmillette]

Closing due to inactivity