HID: multitouch: Add suffix for HID_DG_TOUCHPAD

Instead of printing "UNKNOWN" as device suffix for HID_DG_TOUCHPAD call
the device as "Touchpad".

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Daniel Martin <consume.noise@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-multitouch.c

@@ -968,6 +968,9 @@ static void mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 		case HID_DG_TOUCHSCREEN:
 			/* we do not set suffix = "Touchscreen" */
 			break;
+		case HID_DG_TOUCHPAD:
+			suffix = "Touchpad";
+			break;
 		case HID_GD_SYSTEM_CONTROL:
 			suffix = "System Control";
 			break;