V4L/DVB (13148): uvcvideo: Handle V4L2_CTRL_TYPE_BUTTON control type in VIDIOC_QUERYCTRL

Return minimum, maximum and step set to 0 without querying the hardware.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/uvc/uvc_ctrl.c

@@ -826,6 +826,13 @@ int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
 		ret = 0;
 		goto out;
 
+	case V4L2_CTRL_TYPE_BUTTON:
+		v4l2_ctrl->minimum = 0;
+		v4l2_ctrl->maximum = 0;
+		v4l2_ctrl->step = 0;
+		ret = 0;
+		goto out;
+
 	default:
 		break;
 	}