[CK] Fix out of bounds modifications caused by negative
topk_ids in MoeSortingMultiPhaseKernel_P0_v1 (#6242)
## Motivation
Fix sglang randomly crash by filter negative topk ids.
## Technical Details
In sglang expert parallel mode, there may be idle batch (batch=0) fired,
it will reuse batch=1 resource in cuda graph mode. But in topk op, it
will set non used topk ids to -1, in idle batch case, all topk ids are
set to -1. In `MoeSortingMultiPhaseKernel_P0_v1` negative expert id will
cause overwrite somewhere and sglang may randomly crash.
Except idle batch case, if the captured batch sizes are discrete, there
may be -1 of expert id due to the similar logic.
## Test Plan
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## Test Result
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## Submission Checklist
- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
Co-authored-by: zovonoir <jialzhu@amd.com>
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