ARM: sun8i: a83t: Add device node for SPDIF transmitter

The A83T SoC has an SPDIF transmitter block. According to the vendor
BSP kernel, it is compatible with the one found on the H3 SoC.

Add a device node and pinmux setting for it.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-a83t.dtsi

@@ -202,6 +202,11 @@ mmc0_pins: mmc0-pins {
 				bias-pull-up;
 			};
 
+			spdif_tx_pin: spdif-tx-pin {
+				pins = "PE18";
+				function = "spdif";
+			};
+
 			uart0_pb_pins: uart0-pb-pins {
 				pins = "PB9", "PB10";
 				function = "uart0";
@@ -228,6 +233,22 @@ watchdog@1c20ca0 {
 			clocks = <&osc24M>;
 		};
 
+		spdif: spdif@1c21000 {
+			#sound-dai-cells = <0>;
+			compatible = "allwinner,sun8i-a83t-spdif",
+				     "allwinner,sun8i-h3-spdif";
+			reg = <0x01c21000 0x400>;
+			interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&ccu 44>, <&ccu 76>;
+			resets = <&ccu 32>;
+			clock-names = "apb", "spdif";
+			dmas = <&dma 2>;
+			dma-names = "tx";
+			pinctrl-names = "default";
+			pinctrl-0 = <&spdif_tx_pin>;
+			status = "disabled";
+		};
+
 		uart0: serial@01c28000 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28000 0x400>;