[MUSA]: Add flashinfer sampling backend (#24978)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: zhiguo.qin <zhiguo.qin@mthreads.com>
Co-authored-by: R0CKSTAR <yeahdongcn@gmail.com>

sgl-kernel/python/sgl_kernel/__init__.py

@@ -128,11 +128,13 @@ else:
 
     if hasattr(torch.version, "musa") and torch.version.musa is not None:
         from sgl_kernel.musa import (
+            min_p_sampling_from_probs,
             musa_batched_rotary_embedding_contiguous,
             musa_fused_gemv,
             musa_fused_moe_gemv,
             musa_fused_mul_add,
             musa_rotary_embedding_contiguous,
+            top_k_top_p_sampling_from_probs,
         )
 
     _DEBUG_EXPORT_NAMES = [