northbridge/intel: Do not define include guard as 1

As `#ifndef` and not `#if` is used in the check for
include guards, setting it to 1 is not needed.

Change-Id: Iaa6c0f807b9e99ad3c9551abe4ab1627e5505d67
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/8103
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
Tested-by: build bot (Jenkins)
diff --git a/src/northbridge/intel/gm45/gm45.h b/src/northbridge/intel/gm45/gm45.h
index 673160b..5bdf9e4 100644
--- a/src/northbridge/intel/gm45/gm45.h
+++ b/src/northbridge/intel/gm45/gm45.h
@@ -19,7 +19,7 @@
  */
 
 #ifndef __NORTHBRIDGE_INTEL_GM45_GM45_H__
-#define __NORTHBRIDGE_INTEL_GM45_GM45_H__ 1
+#define __NORTHBRIDGE_INTEL_GM45_GM45_H__
 
 #include "southbridge/intel/i82801ix/i82801ix.h"
 
@@ -434,4 +434,4 @@
 unsigned long northbridge_write_acpi_tables(unsigned long start, struct acpi_rsdp *rsdp);
 #endif
 
-#endif
+#endif /* __NORTHBRIDGE_INTEL_GM45_GM45_H__ */