RISC-V: Update crypto vector ISA info with latest spec

RISC-V: Update crypto vector ISA info with latest spec

This patch add the Zvkb subset of crypto vector extension. The
corresponding test cases have aslo been modified.

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc: Add zvkb ISA info.
	* config/riscv/riscv.opt: Add Mask(ZVKB)

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/zvkn-1.c: Replace zvbb with zvkb.
	* gcc.target/riscv/zvkn.c:   Ditto.
	* gcc.target/riscv/zvknc-1.c:Ditto.
	* gcc.target/riscv/zvknc-2.c:Ditto.
	* gcc.target/riscv/zvknc.c:  Ditto.
	* gcc.target/riscv/zvkng-1.c:Ditto.
	* gcc.target/riscv/zvkng-2.c:Ditto.
	* gcc.target/riscv/zvkng.c:  Ditto.
	* gcc.target/riscv/zvks-1.c: Ditto.
	* gcc.target/riscv/zvks.c:   Ditto.
	* gcc.target/riscv/zvksc-1.c:Ditto.
	* gcc.target/riscv/zvksc-2.c:Ditto.
	* gcc.target/riscv/zvksc.c:  Ditto.
	* gcc.target/riscv/zvksg-1.c:Ditto.
	* gcc.target/riscv/zvksg-2.c:Ditto.
	* gcc.target/riscv/zvksg.c:  Ditto.