x86: baytrail: acpi: Fix I/O APIC ID in the MADT table

So far this is hardcoded to 2, but it should really be read
from the I/O APIC register.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/baytrail/acpi.c

@@ -155,7 +155,7 @@ u32 acpi_fill_madt(u32 current)
 	current += acpi_create_madt_lapics(current);
 
 	current += acpi_create_madt_ioapic((struct acpi_madt_ioapic *)current,
-			2, IO_APIC_ADDR, 0);
+			io_apic_read(IO_APIC_ID) >> 24, IO_APIC_ADDR, 0);
 
 	current += acpi_create_madt_irq_overrides(current);