[Feature] Support DeepSeek MTP on NPU (#11897)

Co-authored-by: liupeng374 <liupeng374@huawei.com>

python/sglang/srt/managers/schedule_batch.py

@@ -77,6 +77,9 @@ from sglang.srt.sampling.sampling_batch_info import SamplingBatchInfo
 from sglang.srt.sampling.sampling_params import SamplingParams
 from sglang.srt.server_args import ServerArgs, get_global_server_args
 from sglang.srt.utils import flatten_nested_list
+from sglang.srt.utils.common import is_npu
+
+_is_npu = is_npu()
 
 if TYPE_CHECKING:
     from sglang.srt.configs.model_config import ModelConfig
@@ -1050,7 +1053,10 @@ class ScheduleBatch(ScheduleBatchDisaggregationDecodeMixin):
     has_grammar: bool = False
 
     # Device
-    device: str = "cuda"
+    if not _is_npu:
+        device: str = "cuda"
+    else:
+        device: str = "npu"
 
     # Speculative decoding
     spec_algorithm: SpeculativeAlgorithm = None