Add the mount-matrix optional property to the binding since it's supported and very useful when using the chip on a board. Signed-off-by: Martin Kepplinger <martink@posteo.de> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20231012142041.253332-1-martink@posteo.de Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>