[diffusion] multi-platform: use current_platform.device_type to replace hard-coded cuda device (#15232)

Signed-off-by: Xiaodong Ye <yeahdongcn@gmail.com>

python/sglang/multimodal_gen/runtime/utils/distributed.py

@@ -7,6 +7,8 @@ import numpy as np
 import torch
 import torch.distributed as dist
 
+from sglang.multimodal_gen.runtime.platforms import current_platform
+
 
 def broadcast_pyobj(
     data: List[Any],
@@ -20,7 +22,7 @@ def broadcast_pyobj(
     of dist_group argument).
     """
     device = torch.device(
-        "cuda" if torch.cuda.is_available() and not force_cpu_device else "cpu"
+        current_platform.device_type if not force_cpu_device else "cpu"
     )
 
     if rank == src: