ARM: add Highbank core platform support

This adds basic support for the Calxeda Highbank platform.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/Kconfig.debug

@@ -128,6 +128,13 @@ choice
 		  Say Y here if you want the debug print routines to direct
 		  their output to the second serial port on these devices.
 
+	config DEBUG_HIGHBANK_UART
+		bool "Kernel low-level debugging messages via Highbank UART"
+		depends on ARCH_HIGHBANK
+		help
+		  Say Y here if you want the debug print routines to direct
+		  their output to the UART on Highbank based devices.
+
 endchoice
 
 config EARLY_PRINTK