ARM: sunxi: Rename uart nodes to serial

The other architecture use serial@address for their uart nodes, so
rename our uart dt nodes to be consistent
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun4i-a10-cubieboard.dts

@@ -36,11 +36,11 @@ led_pins_cubieboard: led_pins@0 {
 			};
 		};
 
-		uart0: uart@01c28000 {
+		uart0: serial@01c28000 {
 			status = "okay";
 		};
 
-		uart1: uart@01c28400 {
+		uart1: serial@01c28400 {
 			status = "okay";
 		};
 	};

arch/arm/boot/dts/sun4i-a10-hackberry.dts

@@ -23,7 +23,7 @@ chosen {
 	};
 
 	soc {
-		uart0: uart@01c28000 {
+		uart0: serial@01c28000 {
 			status = "okay";
 		};
 	};

arch/arm/boot/dts/sun5i-a13-olinuxino.dts

@@ -32,7 +32,7 @@ led_pins_olinuxino: led_pins@0 {
 			};
 		};
 
-		uart1: uart@01c28400 {
+		uart1: serial@01c28400 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&uart1_pins_b>;
 			status = "okay";

arch/arm/boot/dts/sunxi.dtsi

@@ -136,7 +136,7 @@ intc: interrupt-controller@01c20400 {
 			#interrupt-cells = <1>;
 		};
 
-		uart0: uart@01c28000 {
+		uart0: serial@01c28000 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28000 0x400>;
 			interrupts = <1>;
@@ -146,7 +146,7 @@ uart0: uart@01c28000 {
 			status = "disabled";
 		};
 
-		uart1: uart@01c28400 {
+		uart1: serial@01c28400 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28400 0x400>;
 			interrupts = <2>;