x86: acpi: Make irqroute.asl common

The irqroute.asl file is already common enough to all x86 platforms.
Platform ASL files need only provide a irqroute.h to describe how
internal PCI devices and PCIe downstream port devices' INTx pins are
routed to which PIRQ pin.

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

arch/x86/include/asm/acpi/irq_helper.h

@@ -108,4 +108,4 @@ Device (prefix_ ## 0 ## func_) \
 }
 
 /* SoC specific PIRQ route configuration */
-#include "irqroute.h"
+#include <asm/arch/acpi/irqroute.h>

arch/x86/include/asm/arch-baytrail/acpi/southcluster.asl

@@ -207,5 +207,5 @@ Device (PCI0)
 	#include "xhci.asl"
 
 	/* IRQ routing for each PCI device */
-	#include "irqroute.asl"
+	#include <asm/acpi/irqroute.asl>
 }