mvebu: Migrate CONFIG_DDR_32BIT/64BIT to Kconfig

Move CONFIG_DDR_32BIT/64BIT to Kconfig as a choice for Armada XP
platforms.  Make 64bit the default as this mirrors the current code.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index 89737a3..1daa647 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -184,6 +184,19 @@
 
 endchoice
 
+choice
+	prompt "DDR bus width"
+	default DDR_64BIT
+	depends on ARMADA_XP
+
+config DDR_64BIT
+	bool "64bit bus width"
+
+config DDR_32BIT
+	bool "32bit bus width"
+
+endchoice
+
 config SYS_BOARD
 	default "clearfog" if TARGET_CLEARFOG
 	default "helios4" if TARGET_HELIOS4