package a new USE_NO_KERNEL_OP for USE_OP_ITSELF

[luotao1]

Currently, there are two USE_OP_ITSELF ops.

USE_OP_ITSELF(recurrent);
USE_OP_ITSELF(identity);

And the diffence between USE_OP_ITSELF and USE_OP is whether ops has kernel.

#define USE_OP(op_type)   \
  USE_OP_ITSELF(op_type); \
  USE_OP_KERNEL(op_type)

However, USE_OP and USE_CPU_ONLY_OP are the same level, USE_OP_ITSELF is a sub-level in USE_OP currently.

Discussing with @Canpio , we will package a new USE_NO_KERNEL_OP for USE_OP_ITSELF. Thus, when adding new ops, developers can use one of USE_OP , USE_CPU_ONLY_OP and USE_NO_KERNEL_OP to register.