Refactor device determination to function; add MPS fallback

sdxl_minimal_inference.py

@@ -10,6 +10,7 @@ from einops import repeat
 import numpy as np
 import torch
 
+from library.device_utils import get_preferred_device
 from library.ipex_interop import init_ipex
 
 init_ipex()
@@ -85,7 +86,7 @@ if __name__ == "__main__":
     guidance_scale = 7
     seed = None  # 1
 
-    DEVICE = "cuda"
+    DEVICE = get_preferred_device()
     DTYPE = torch.float16  # bfloat16 may work
 
     parser = argparse.ArgumentParser()