message: fix lstm ut of bf16 cpu path
diff: @@ -261,10 +261,10 @@ class TestLSTM(TestCase):
  with ipex.amp.autocast(enabled=bf16, configure=ipex.conf.AmpConf(torch.bfloat16)):
  if empty_state:
  - y, hy = model(self._cast_dtype(input, bf16))
  + y, hy = self._cast_dtype(model, bf16)(self._cast_dtype(input, bf16))
  y_ipex, hy_ipex = model_ipex(input)
  else:
  - y, hy = model(input, (self._cast_dtype(h, bf16), self._cast_dtype(c, bf16)))
  + y, hy = self._cast_dtype(model, bf16)(self._cast_dtype(input, bf16), (self._cast_dtype(h, bf16), self._cast_dtype(c, bf16)))
  y_ipex, hy_ipex = model_ipex(input, (h, c))
  if not training and bf16:
  