The UART0's interrupt vector is wrongly set to 1 in the device tree.
Use SIFIVE_U_UART0_IRQ instead.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>