arm: s5p4418: dm_serial: add uarts to dts

Add S5P4418 UARTs and appropriate pinctrl to dts. Add UART to
s5p4418-nanopi2.dts.

Signed-off-by: Stefan Bosch <stefan_b@posteo.net>
diff --git a/arch/arm/dts/s5p4418-pinctrl.dtsi b/arch/arm/dts/s5p4418-pinctrl.dtsi
index a7e1c2c..0768d80 100644
--- a/arch/arm/dts/s5p4418-pinctrl.dtsi
+++ b/arch/arm/dts/s5p4418-pinctrl.dtsi
@@ -132,4 +132,75 @@
 		pin-pull = <2>;
 		pin-strength = <0>;
 	};
+
+	/* UART */
+	uart0_rx:uart0-rx {
+		pins = "gpiod-14";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart0_tx:uart0-tx {
+		pins = "gpiod-18";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart1_rx:uart1-rx {
+		pins = "gpiod-15";
+		pin-function = <2>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart1_tx:uart1-tx {
+		pins = "gpiod-19";
+		pin-function = <2>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart2_rx:uart2-rx {
+		pins = "gpiod-16";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart2_tx:uart2-tx {
+		pins = "gpiod-20";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart3_rx:uart3-rx {
+		pins = "gpiod-17";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart3_tx:uart3-tx {
+		pins = "gpiod-21";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart4_rx:uart4-rx {
+		pins = "gpiob-28";
+		pin-function = <3>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
+
+	uart4_tx:uart4-tx {
+		pins = "gpiob-29";
+		pin-function = <3>;
+		pin-pull = <2>;
+		pin-strength = <0>;
+	};
 };