[Patch v4] x86, irq: Fix build error caused by 9eabc99a635a77cbf09

[Jiang Liu <jiang.liu@linux.intel.com>]

Commit 9eabc99a635a77cbf09 causes following build error when
IOAPIC is disabled.
   arch/x86/pci/irq.c: In function 'pirq_disable_irq':
>> arch/x86/pci/irq.c:1259:2: error: implicit declaration of function 'mp_should_keep_irq' [-Werror=implicit-function-declaration]
     if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
     ^
   cc1: some warnings being treated as errors

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
Hi Thomas and HPA,
	Really sorry about this. I only tested CONFIG_PM_RUNTIME,
but forgot CONFIG_X86_IO_APIC. Could you please help to merge or
fold this patch?
Regards!
Gerry
---
 arch/x86/include/asm/io_apic.h |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 478c490f3654..1733ab49ac5e 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -239,6 +239,7 @@ static inline int mp_find_ioapic(u32 gsi) { return 0; }
 static inline u32 mp_pin_to_gsi(int ioapic, int pin) { return UINT_MAX; }
 static inline int mp_map_gsi_to_irq(u32 gsi, unsigned int flags) { return gsi; }
 static inline void mp_unmap_irq(int irq) { }
+static inline bool mp_should_keep_irq(struct device *dev) { return 1; }
 
 static inline int save_ioapic_entries(void)
 {
-- 
1.7.10.4