fix rwkv v5 fp16 (#10474)

python/llm/src/bigdl/llm/transformers/convert.py

@@ -538,6 +538,7 @@ def _optimize_pre(model):
     # for rwkv models (verified RWKV/rwkv-4-world-7b)
     if model.config.model_type == "rwkv":
         model.rwkv._rescale_layers()
+        model.rwkv.layers_are_rescaled = True
     # process NormHead module in Baichuan2 7B and 13B
     if model.config.model_type == "baichuan" and model.config.vocab_size == 125696:
         # NormHead do normalization on the weights just once at inference time.