target/riscv: rvv-1.0: add mstatus VS field

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-4-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu_bits.h

@@ -375,6 +375,7 @@
 #define MSTATUS_UBE         0x00000040
 #define MSTATUS_MPIE        0x00000080
 #define MSTATUS_SPP         0x00000100
+#define MSTATUS_VS          0x00000600
 #define MSTATUS_MPP         0x00001800
 #define MSTATUS_FS          0x00006000
 #define MSTATUS_XS          0x00018000