riscv: sifive_u: Correct UART0's IRQ in the device tree

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

hw/riscv/sifive_u.c

@@ -244,7 +244,7 @@ static void create_fdt(SiFiveUState *s, const struct MemmapEntry *memmap,
     qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency",
                           SIFIVE_U_CLOCK_FREQ / 2);
     qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", plic_phandle);
-    qemu_fdt_setprop_cells(fdt, nodename, "interrupts", 1);
+    qemu_fdt_setprop_cells(fdt, nodename, "interrupts", SIFIVE_U_UART0_IRQ);
 
     qemu_fdt_add_subnode(fdt, "/chosen");
     qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);