ARM: ux500: define serial port aliases

This enumerates the PL011 serial ports on the Ux500. This is
necessary to do if we want to remove one of the serial ports,
since userspace depends on console to be present on ttyAMA2
and we must not break userspace.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/arm/boot/dts/ste-snowball.dts b/arch/arm/boot/dts/ste-snowball.dts
index 9edadc3..acf14ce 100644
--- a/arch/arm/boot/dts/ste-snowball.dts
+++ b/arch/arm/boot/dts/ste-snowball.dts
@@ -18,6 +18,13 @@
 	model = "Calao Systems Snowball platform with device tree";
 	compatible = "calaosystems,snowball-a9500", "st-ericsson,u9500";
 
+	/* This stablilizes the serial port enumeration */
+	aliases {
+		serial0 = &ux500_serial0;
+		serial1 = &ux500_serial1;
+		serial2 = &ux500_serial2;
+	};
+
 	memory {
 		reg = <0x00000000 0x20000000>;
 	};