arm64: dts: renesas: r8a77990: ebisu: Remove clkout-lr-synchronous from sound

rcar_sound doesn't support clkout-lr-synchronous in upstream.
It was supported under out-of-tree rcar_sound.
upstream rcar_sound is supporting
	- clkout-lr-synchronous
	+ clkout-lr-asynchronous
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87mubt3tux.wl-kuninori.morimoto.gx@renesas.com
Fixes: 56629fcb ("arm64: dts: renesas: ebisu: Enable Audio")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts

@@ -634,7 +634,6 @@ &rcar_sound {
 	/* audio_clkout0/1/2/3 */
 	#clock-cells = <1>;
 	clock-frequency = <12288000 11289600>;
-	clkout-lr-synchronous;
 
 	status = "okay";