arm64: dts: rockchip: add i2s0-2ch-bus pins on rk3399

Add pin definition for I2S0 if used as a 2-channel only bus.
Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -2043,6 +2043,16 @@ i2c8_xfer: i2c8-xfer {
 		};
 
 		i2s0 {
+			i2s0_2ch_bus: i2s0-2ch-bus {
+				rockchip,pins =
+					<3 24 RK_FUNC_1 &pcfg_pull_none>,
+					<3 25 RK_FUNC_1 &pcfg_pull_none>,
+					<3 26 RK_FUNC_1 &pcfg_pull_none>,
+					<3 27 RK_FUNC_1 &pcfg_pull_none>,
+					<3 31 RK_FUNC_1 &pcfg_pull_none>,
+					<4 0 RK_FUNC_1 &pcfg_pull_none>;
+			};
+
 			i2s0_8ch_bus: i2s0-8ch-bus {
 				rockchip,pins =
 					<3 24 RK_FUNC_1 &pcfg_pull_none>,