The "renesas,rcar_sound" compatible property value was never processed
nor documented.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>