x86: Write correct bus number for the irq router

We should write correct bus number to the PIRQ routing table for the
irq router from device tree, instead of hard-coded zero.

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

arch/x86/cpu/irq.c

@@ -161,7 +161,7 @@ static int create_pirq_routing_table(void)
 	/* Populate the PIRQ table fields */
 	rt->signature = PIRQ_SIGNATURE;
 	rt->version = PIRQ_VERSION;
-	rt->rtr_bus = 0;
+	rt->rtr_bus = PCI_BUS(irq_router.bdf);
 	rt->rtr_devfn = (PCI_DEV(irq_router.bdf) << 3) |
 			PCI_FUNC(irq_router.bdf);
 	rt->rtr_vendor = PCI_VENDOR_ID_INTEL;