arm64: dts: renesas: rzg2l-smarc: Add WM8978 sound codec

Add WM8978 sound codec node to RZ/G2L SMARC EVK.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20210921084605.16250-3-biju.das.jz@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/rzg2l-smarc.dtsi

@@ -65,8 +65,15 @@ &i2c1 {
 &i2c3 {
 	pinctrl-0 = <&i2c3_pins>;
 	pinctrl-names = "default";
+	clock-frequency = <400000>;
 
 	status = "okay";
+
+	wm8978: codec@1a {
+		compatible = "wlf,wm8978";
+		#sound-dai-cells = <0>;
+		reg = <0x1a>;
+	};
 };
 
 &ohci0 {