target/riscv: Adjust trans_rev8_32 for riscv64

target/riscv: Adjust trans_rev8_32 for riscv64

When target_long is 64-bit, we still want a 32-bit bswap for rev8.
Since this opcode is specific to RV32, we need not conditionalize.

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-12-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>