arm64: dts: sun50i: sopine-baseboard: Expose serial1, serial2 and serial3

Follow what the sun50i-a64-pine64.dts does and expose all 5 serial
connections.
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Maxime Ripard <mripard@kernel.org>

arch/arm64/boot/dts/allwinner/sun50i-a64-sopine-baseboard.dts

@@ -55,6 +55,10 @@ / {
 	aliases {
 		ethernet0 = &emac;
 		serial0 = &uart0;
+		serial1 = &uart1;
+		serial2 = &uart2;
+		serial3 = &uart3;
+		serial4 = &uart4;
 	};
 
 	chosen {
@@ -204,6 +208,27 @@ &uart0 {
 	status = "okay";
 };
 
+/* On Pi-2 connector */
+&uart2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart2_pins>;
+	status = "disabled";
+};
+
+/* On Euler connector */
+&uart3 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart3_pins>;
+	status = "disabled";
+};
+
+/* On Euler connector, RTS/CTS optional */
+&uart4 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart4_pins>;
+	status = "disabled";
+};
+
 &usb_otg {
 	dr_mode = "host";
 	status = "okay";