Remove fp16 restriction in the docstring for DeepSpeedStrategy (#13919)

Co-authored-by: Akihiro Nitta <[email protected]>
Co-authored-by: awaelchli <[email protected]>

Author: 3 people

src/pytorch_lightning/strategies/deepspeed.py

@@ -152,7 +152,8 @@ def __init__(
 
         Arguments:
 
-            zero_optimization: Enable ZeRO optimization. This is only compatible with precision=16.
+            zero_optimization: Enable ZeRO optimization. This is compatible with either `precision=16` or
+                `precision="bf16"`.
 
             stage: Different stages of the ZeRO Optimizer. 0 is disabled,
                 1 is optimizer state partitioning, 2 is optimizer+gradient state partitioning,