[EP] add rdma atomic to low-latency#644

MaoZiming wants to merge 2 commits intoep-debug-amd-mem-consistencyuccl-project/uccl:ep-debug-amd-mem-consistencyfrom

ep-debug-amd-mem-consistency-add-ll-rdma-atomicuccl-project/uccl:ep-debug-amd-mem-consistency-add-ll-rdma-atomicCopy head branch name to clipboard