[CK_TILE] moe_sorting support "local_tokens" feature for EP case

[carlushuang]

Proposed changes

support token passed in from another GPU buffer, this is used for EP case dispatch/combine where the remote ranks may receive different num of tokens

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.

• I have added tests relevant to the introduced functionality, and the unit tests are passing locally
• 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.
• I have added inline documentation which enables the maintainers with understanding the motivation
• I have removed the stale documentation which is no longer relevant after this pull request
• (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
• I have run clang-format on all changed files
• 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

[spolifroni-amd]

The readme needs a bit of smoothing, contextualizing, and clarification.

I think all the comments have been addressed adequately.