udoo: Switch to SPL support

Currently we need to build one U-boot image for each of the udoo
variants: quad and dual-lite.

By switching to SPL we can support all two variants with a single binary.

Based on the SPL for wandboard.

Tested with OpenELEC (Open Embedded Linux Entertainment Center)
on both boards.

Signed-off-by: Peter Vicman <peter.vicman@gmail.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Peter Vicman <peter.vicman@gmail.com>
Acked-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cd88df4..ed8fd36 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -514,6 +514,7 @@
 config TARGET_UDOO
 	bool "Support udoo"
 	select CPU_V7
+	select SUPPORT_SPL
 
 config TARGET_WANDBOARD
 	bool "Support wandboard"