ARM: mvebu: add serial port aliases on Armada 370/375/38x/XP

This commit adds 'serialX' aliases for the various serial ports on
Armada 370, 375, 38x and XP platforms. It will allow the usage of the
stdout-path property.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi
index 975ae64..bbabee5 100644
--- a/arch/arm/boot/dts/armada-xp.dtsi
+++ b/arch/arm/boot/dts/armada-xp.dtsi
@@ -57,6 +57,8 @@
 	compatible = "marvell,armadaxp", "marvell,armada-370-xp";
 
 	aliases {
+		serial2 = &uart2;
+		serial3 = &uart3;
 	};
 
 	soc {