ACPI / video: Add a quirk to force acpi-video backlight on SAMSUNG 530U4E/540U4E

The native interface on SAMSUNG 530U4E/540U4E doesn't work even though
the firmware claims Win8 compatible while the acpi_video interface
works, add a quirk for this.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=108971
Reported-and-tested-by: adam bk <adamdd55@gmail.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 8fe2682..90e2d54 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -250,6 +250,15 @@
 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
 		},
 	},
+	{
+	 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
+	 .callback = video_detect_force_video,
+	 .ident = "SAMSUNG 530U4E/540U4E",
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
+		},
+	},
 
 	/* Non win8 machines which need native backlight nevertheless */
 	{