irq_remap: Fix compiler warning with CONFIG_IRQ_REMAP=y

Fix the below compiler warning:

arch/x86/include/asm/irq_remapping.h:72:19: warning: ‘struct IO_APIC_route_entry’ declared inside parameter list [enabled by default]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: joro@8bytes.org
Cc: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1336460934-23592-1-git-send-email-suresh.b.siddha@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/include/asm/irq_remapping.h

@@ -22,11 +22,9 @@
 #ifndef __X86_IRQ_REMAPPING_H
 #define __X86_IRQ_REMAPPING_H
 
-#ifdef CONFIG_IRQ_REMAP
+#include <asm/io_apic.h>
 
-struct IO_APIC_route_entry;
-struct io_apic_irq_attr;
-struct pci_dev;
+#ifdef CONFIG_IRQ_REMAP
 
 extern int irq_remapping_enabled;