[fluid_ops] clean c_reduce_prod (#70300)

Author: co63oc

paddle/fluid/operators/collective/c_reduce_prod_op.cc

@@ -39,13 +39,3 @@ namespace ops = paddle::operators;
 REGISTER_OP_WITHOUT_GRADIENT(c_reduce_prod,
                              ops::CReduceOp,
                              ops::CReduceProdOpMaker);
-
-PD_REGISTER_STRUCT_KERNEL(c_reduce_prod,
-                          CPU,
-                          ALL_LAYOUT,
-                          ops::CReduceProdCPUKernel,
-                          float,
-                          double,
-                          int,
-                          int64_t,
-                          phi::dtype::float16) {}