arm64: dts: meson: sei510: add max98357a DAC

The SEI510 board features a max98357a audio codec for built-in
speaker
Signed-off-by: NMaxime Jourdan <mjourdan@baylibre.com>
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-g12a-sei510.dts

@@ -32,6 +32,13 @@
 		ethernet0 = &ethmac;
 	};
 
+	mono_dac: audio-codec {
+		compatible = "maxim,max98357a";
+		#sound-dai-cells = <0>;
+		sound-name-prefix = "U16";
+		sdmode-gpios = <&gpio GPIOX_8 GPIO_ACTIVE_HIGH>;
+	};
+
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};