target/riscv: Add the privileged spec version 1.12.0

Add the definition for ratified privileged specification version v1.12

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220303185440.512391-3-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.h

@@ -86,6 +86,7 @@ enum {
 enum {
     PRIV_VERSION_1_10_0 = 0,
     PRIV_VERSION_1_11_0,
+    PRIV_VERSION_1_12_0,
 };
 
 #define VEXT_VERSION_1_00_0 0x00010000