Index: sys/compat/linuxkpi/common/include/acpi/video.h
===================================================================
--- sys/compat/linuxkpi/common/include/acpi/video.h
+++ sys/compat/linuxkpi/common/include/acpi/video.h
@@ -35,4 +35,7 @@
 
 #define	ACPI_VIDEO_NOTIFY_PROBE	0x81
 
+#define	acpi_video_register()	0
+#define	acpi_video_unregister()	0
+
 #endif	/* _LINUXKPI_ACPI_VIDEO_H_ */