RISC-V: Add option defines for Scalar Cryptography

RISC-V: Add option defines for Scalar Cryptography

gcc/ChangeLog:

2021-11-21  SiYu Wu  <siyu@isrc.iscas.ac.cn>

	* common/config/riscv/riscv-common.c (riscv_ext_version_table):
	Add zbk* and zk*.
	* config/riscv/riscv-opts.h (MASK_ZBKB): New.
	(MASK_ZBKC): Ditto.
	(MASK_ZBKX): Ditto.
	(MASK_ZKNE): Ditto.
	(MASK_ZKND): Ditto.
	(MASK_ZKNH): Ditto.
	(MASK_ZKR): Ditto.
	(MASK_ZKSED): Ditto.
	(MASK_ZKSH): Ditto.
	(MASK_ZKT): Ditto.
	(TARGET_ZBKB): Ditto.
	(TARGET_ZBKC): Ditto.
	(TARGET_ZBKX): Ditto.
	(TARGET_ZKNE): Ditto.
	(TARGET_ZKND): Ditto.
	(TARGET_ZKNH): Ditto.
	(TARGET_ZKR): Ditto.
	(TARGET_ZKSED): Ditto.
	(TARGET_ZKSH): Ditto.
	(TARGET_ZKT): Ditto.
	* config/riscv/riscv.opt (riscv_zk_subext): New.