ACPI: video: Add backlight=native DMI quirk for Dell Studio 1569

The Dell Studio 1569 predates Windows 8, so it defaults to using
acpi_video# for backlight control, but this is non functional on
this model.

Add a DMI quirk to use the native intel_backlight interface which
does work properly.
Reported-by: raycekarneal <raycekarneal@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/video_detect.c

@@ -528,6 +528,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
 		},
 	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Dell Studio 1569 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1569"),
+		},
+	},
 	{
 	 .callback = video_detect_force_native,
 	 /* Acer Aspire 3830TG */