add npu support dtypes (#4223)

Co-authored-by: Njializheng <jializheng@huawei.com>

accelerator/npu_accelerator.py

@@ -134,6 +134,9 @@ class NPU_Accelerator(DeepSpeedAccelerator):
     def is_fp16_supported(self):
         return True
 
+    def supported_dtypes(self):
+        return [torch.float, torch.half, torch.bfloat16]
+
     # Misc
     def amp(self):
         if hasattr(torch.npu, 'amp'):