drm/nouveau: Remove duplicate ACPI_VIDEO_NOTIFY_PROBE definition

Commit 3a6536c ("drm/nouveau: Intercept ACPI_VIDEO_NOTIFY_PROBE")
added a definition of ACPI_VIDEO_NOTIFY_PROBE because <acpi/video.h> didn't
supply one.  Later, commit eff4a75 ("ACPI / video: Move
ACPI_VIDEO_NOTIFY_* defines to acpi/video.h") moved ACPI_VIDEO_NOTIFY_PROBE
and other definitions to <acpi/video.h>, so the copy in nouveau_display.c
is now unnecessary.

Remove the unnecessary definition from nouveau_display.c.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Hans de Goede <hdegoede@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -358,15 +358,6 @@ nouveau_display_hpd_work(struct work_struct *work)
 
 #ifdef CONFIG_ACPI
 
-/*
- * Hans de Goede: This define belongs in acpi/video.h, I've submitted a patch
- * to the acpi subsys to move it there from drivers/acpi/acpi_video.c .
- * This should be dropped once that is merged.
- */
-#ifndef ACPI_VIDEO_NOTIFY_PROBE
-#define ACPI_VIDEO_NOTIFY_PROBE			0x81
-#endif
-
 static int
 nouveau_display_acpi_ntfy(struct notifier_block *nb, unsigned long val,
 			  void *data)