ARM: at91/dt: at91-kizbox: user proper serial uart

USART3 is the only serial UART accessible.
Signed-off-by: NGaël PORTAY <g.portay@overkiz.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/at91-kizbox.dts

@@ -38,14 +38,6 @@
 
 	ahb {
 		apb {
-			usart0: serial@fffb0000 {
-				status = "okay";
-			};
-
-			usart1: serial@fffb4000 {
-				status = "okay";
-			};
-
 			macb0: ethernet@fffc4000 {
 				phy-mode = "mii";
 				pinctrl-0 = <&pinctrl_macb_rmii
@@ -53,6 +45,10 @@
 				status = "okay";
 			};
 
+			usart3: serial@fffd0000 {
+				status = "okay";
+			};
+
 			dbgu: serial@fffff200 {
 				status = "okay";
 			};