ARM: mxs: Fix UARTs on M28EVK

Make use of RTS/CTS lines on AUART0 and register AUART1 and AUART2
which are routed onto a pin header.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx28-m28evk.dts

@@ -220,7 +220,19 @@
 
 			auart0: serial@8006a000 {
 				pinctrl-names = "default";
-				pinctrl-0 = <&auart0_2pins_a>;
+				pinctrl-0 = <&auart0_pins_a>;
+				status = "okay";
+			};
+
+			auart1: serial@8006c000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&auart1_pins_a>;
+				status = "okay";
+			};
+
+			auart2: serial@8006e000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&auart2_2pins_b>;
 				status = "okay";
 			};
 		};