target/riscv: Set default XLEN for hypervisor

target/riscv: Set default XLEN for hypervisor

When swap regs for hypervisor, the value of vsstatus or mstatus_hs
should have the right XLEN. Otherwise, it will propagate to mstatus.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220120122050.41546-22-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>