【Prim】Fix dropout CINN amp error (#51688)

* support amp logic for layer_norm and softmax

* fix layer_norm amp

* fix layernorm api and dropout fp16

* fix layernorm api and dropout fp16

* fix bn, ln dtype in float16

* fix dropout fp16

* fix comment

* fix cinn dropout amp error

python/paddle/incubate/autograd/composite_rules.py

@@ -355,10 +355,14 @@ def dropout_composite(x, seed_tensor, p, is_test, mode, seed, fix_seed):
 
 
 def bernoulli(shape, dtype, p, seed=0):
+    from paddle.fluid.data_feeder import convert_dtype
+
+    # TODO(jiabin) Fix uniform doesn't support float16 error in CINN
+    new_dtype = "float32" if convert_dtype(dtype) == "float16" else dtype
     return cast(
         greater_equal(
-            uniform(shape, dtype, min=0.0, max=1.0, seed=seed),
-            fill_constant(shape, dtype, p),
+            uniform(shape, new_dtype, min=0.0, max=1.0, seed=seed),
+            fill_constant(shape, new_dtype, p),
         ),
         dtype,
     )