x86: x2apic, IR: Clean up X86_X2APIC and INTR_REMAP config checks

Add x2apic_supported() to clean up CONFIG_X86_X2APIC checks.

Fix CONFIG_INTR_REMAP checks.

[ Impact: cleanup ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: dwmw2@infradead.org
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Weidong Han <weidong.han@intel.com>
LKML-Reference: <20090420200450.128993000@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 06f592a..10ff5c4 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -158,6 +158,8 @@
 }
 #define irq_remapped(irq)		(0)
 #define enable_intr_remapping(mode)	(-1)
+#define disable_intr_remapping()	(0)
+#define reenable_intr_remapping(mode)	(0)
 #define intr_remapping_enabled		(0)
 #endif