Fix build error when CONFIG_ACPI is not set/enabled:

../arch/x86/pci/xen.c: In function ‘pci_xen_init’:
../arch/x86/pci/xen.c:410:2: error: implicit declaration of function ‘acpi_noirq_set’; did you mean ‘acpi_irq_get’? [-Werror=implicit-function-declaration]
  acpi_noirq_set();

Fixes: 88e9ca1 ("xen/pci: Use acpi_noirq_set() helper to avoid #ifdef")
Signed-off-by: Randy Dunlap <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Juergen Gross <[email protected]>

Author: rddunlap

arch/x86/pci/xen.c

@@ -26,6 +26,7 @@
 #include <asm/xen/pci.h>
 #include <asm/xen/cpuid.h>
 #include <asm/apic.h>
+#include <asm/acpi.h>
 #include <asm/i8259.h>
 
 static int xen_pcifront_enable_irq(struct pci_dev *dev)