RISC-V: KVM: Allow Zicbop extension for Guest/VM

RISC-V: KVM: Allow Zicbop extension for Guest/VM

Extend the KVM ISA extension ONE_REG interface to allow KVM user space
to detect and enable Zicbop extension for Guest/VM.

Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Nutty Liu <nutty.liu@hotmail.com>
Reviewed-by: Nutty Liu <liujingqi@lanxincomputing.com>
Link: https://lore.kernel.org/r/db4a9b679cc653bb6f5f5574e4196de7a980e458.1754646071.git.zhouquan@iscas.ac.cn
Signed-off-by: Anup Patel <anup@brainfault.org>