yaml: fix Marlin AssertionError

Marlin quantized linear only supports GPU device, when change generate_op
to "KLinearMarlin", generate_device need to be changed to "cuda" accordingly.

Fixes: e5b001d7 ("Update readme; Format code; Add example yaml.")

ktransformers/optimize/optimize_rules/DeepSeek-V2-Lite-Chat.yaml

@@ -22,7 +22,7 @@
   replace:
     class: ktransformers.operators.linear.KTransformersLinear
     kwargs:
-      generate_device: "cpu"
+      generate_device: "cuda"
       prefill_device: "cuda"
       generate_op: "KLinearMarlin"
       prefill_op: "KLinearTorch"