Fix autogaze_model_id: bfshi/AutoGaze no longer exists

Loading this model's processor currently fails because it tries to pull AutoGaze from `bfshi/AutoGaze`, which isn't on the Hub anymore (looks like it used to be on @bfshi 's personal account before moving to `nvidia/AutoGaze`):

```
RepositoryNotFoundError: 404 Client Error.
Repository Not Found for url: https://huggingface.co/api/models/bfshi/AutoGaze
```

Changed `autogaze_model_id` in `preprocessor_config.json` and the fallback in `processing_nvila.py` to `nvidia/AutoGaze`. Until now I've had to patch these two files locally every time I use the model.

Same problem in the AutoGaze quick start docs, fix open here: https://github.com/NVlabs/AutoGaze/pull/6

preprocessor_config.json

@@ -24,7 +24,7 @@
     "height": 392,
     "width": 392
   },
-  "autogaze_model_id": "bfshi/AutoGaze",
+  "autogaze_model_id": "nvidia/AutoGaze",
   "gazing_ratio_tile": 0.75,
   "gazing_ratio_thumbnail": 0.75,
   "task_loss_requirement_tile": 0.7,

processing_nvila.py

@@ -142,7 +142,7 @@ class NVILAProcessor(ProcessorMixin):
         self.tokenizer: Qwen2Tokenizer | Qwen2TokenizerFast
         
         # AutoGaze configuration
-        self.autogaze_model_id = autogaze_model_id or "bfshi/AutoGaze"
+        self.autogaze_model_id = autogaze_model_id or "nvidia/AutoGaze"
         self.gazing_ratio_tile = gazing_ratio_tile
         self.gazing_ratio_thumbnail = gazing_ratio_thumbnail
         self.task_loss_requirement_tile = task_loss_requirement_tile