hw/intc: sifive_clint: Use RISC-V CPU GPIO lines

hw/intc: sifive_clint: Use RISC-V CPU GPIO lines

Instead of using riscv_cpu_update_mip() let's instead use the new RISC-V
CPU GPIO lines to set the timer and soft MIP bits.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-id: 946e1ef5e268b24084c7ddad84c146de62a56736.1630301632.git.alistair.francis@wdc.com