[Fix] Add speculative_draft_model_revision to server_args (#5255)

Signed-off-by: Devashish Lal <devashish@rivosinc.com>

python/sglang/srt/configs/model_config.py

@@ -302,11 +302,16 @@ class ModelConfig:
         ) or getattr(self.hf_config, "image_token_index", None)
 
     @staticmethod
-    def from_server_args(server_args: ServerArgs, model_path: str = None, **kwargs):
+    def from_server_args(
+        server_args: ServerArgs,
+        model_path: str = None,
+        model_revision: str = None,
+        **kwargs,
+    ):
         return ModelConfig(
             model_path=model_path or server_args.model_path,
             trust_remote_code=server_args.trust_remote_code,
-            revision=server_args.revision,
+            revision=model_revision or server_args.revision,
             context_length=server_args.context_length,
             model_override_args=server_args.json_model_override_args,
             is_embedding=server_args.is_embedding,