Fix idefics default. (#1614)

# What does this PR do?

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Fixes # (issue)


## Before submitting
- [ ] This PR fixes a typo or improves...

server/text_generation_server/models/idefics.py

@@ -40,7 +40,7 @@ class IDEFICSSharded(IdeficsCausalLM):
             device = torch.device(f"cuda:{rank}")
             # 9b seems to work correctly enough in float16, but 80b seems
             # to be really saturating for f16.
-            dtype = torch.bfloat16 if dtype is None else dtype
+            dtype = torch.float16 if dtype is None else dtype
         else:
             device = torch.device("cpu")
             dtype = torch.float32 if dtype is None else dtype