[ROCm] enable moe topk softmax in amd (#4448)

sgl-kernel/csrc/torch_extension_rocm.cc

@@ -61,6 +61,10 @@ TORCH_LIBRARY_EXPAND(sgl_kernel, m) {
       "moe_align_block_size(Tensor topk_ids, int num_experts, int block_size, Tensor! sorted_token_ids, Tensor! "
       "experts_ids, Tensor! num_tokens_post_pad, Tensor! token_cnts_buffer, Tensor! cumsum_buffer) -> ()");
   m.impl("moe_align_block_size", torch::kCUDA, &moe_align_block_size);
+  m.def(
+      "topk_softmax(Tensor! topk_weights, Tensor! topk_indices, Tensor! "
+      "token_expert_indices, Tensor gating_output) -> ()");
+  m.impl("topk_softmax", torch::kCUDA, &topk_softmax);
 }
 
 REGISTER_EXTENSION(common_ops)

sgl-kernel/setup_rocm.py

@@ -41,6 +41,7 @@ include_dirs = [
 sources = [
     "csrc/allreduce/custom_all_reduce.hip",
     "csrc/moe/moe_align_kernel.cu",
+    "csrc/moe/moe_topk_softmax_kernels.cu",
     "csrc/torch_extension_rocm.cc",
 ]