arm64: dts: bitmain: Add UART pinctrl support for Sophon Edge

Add pinctrl support for UARTs exposed on the Sophon Edge board.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm64/boot/dts/bitmain/bm1880-sophon-edge.dts

@@ -148,17 +148,46 @@ portc: gpio-controller@0 {
 	};
 };
 
+&pinctrl {
+	pinctrl_uart0_default: pinctrl-uart0-default {
+		pinmux {
+			groups = "uart0_grp";
+			function = "uart0";
+		};
+	};
+
+	pinctrl_uart1_default: pinctrl-uart1-default {
+		pinmux {
+			groups = "uart1_grp";
+			function = "uart1";
+		};
+	};
+
+	pinctrl_uart2_default: pinctrl-uart2-default {
+		pinmux {
+			groups = "uart2_grp";
+			function = "uart2";
+		};
+	};
+};
+
 &uart0 {
 	status = "okay";
 	clocks = <&uart_clk>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_uart0_default>;
 };
 
 &uart1 {
 	status = "okay";
 	clocks = <&uart_clk>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_uart1_default>;
 };
 
 &uart2 {
 	status = "okay";
 	clocks = <&uart_clk>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_uart2_default>;
 };