Update chronos.py - model.device (#11)

*Issue #, if available:* N/A

*Description of changes:*

Thanks for the very clean impl of the Model, Tokenizer, and Pipeline. 

I was curios about it and found a minor improvement in the API - what do
you think about it? Feel free to close. Change is untested.

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copy, and redistribute this contribution, under the terms of your
choice.

src/chronos/chronos.py

@@ -204,7 +204,10 @@ class ChronosModel(nn.Module):
         super().__init__()
         self.config = config
         self.model = model
-        self.device = model.device
+
+    @property
+    def device(self):
+        return self.model.device
 
     def forward(
         self,