ACPI / video: Add "Asus UL30VT" to ACPI video detect blacklist

The ACPI video driver can't control backlight correctly on
Asus UL30VT.  Vendor driver (asus-laptop) can work.  This patch is to
add "Asus UL30VT" to ACPI video detect blacklist in order to use
asus-laptop for video control on the "Asus UL30VT" rather than ACPI
video driver.

References: https://bugzilla.kernel.org/show_bug.cgi?id=32592
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/video_detect.c

@@ -156,6 +156,14 @@ static struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_BOARD_NAME, "X360"),
 		},
 	},
+	{
+	.callback = video_detect_force_vendor,
+	.ident = "Asus UL30VT",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
+		},
+	},
 	{ },
 };