Adds dt-binding for a Generic MIDI Interface using a serial device. Signed-off-by: Daniel Kaehn <kaehndan@gmail.com> Reviewed-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220509145933.1161526-2-kaehndan@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>