avr32: Change Atmel ATNGW100 config to add choice of add-on board

Signed-off-by: Peter Ma <pma@mediamatech.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/boards/atngw100/Kconfig

@@ -2,8 +2,15 @@
 
 if BOARD_ATNGW100
 
+choice
+	prompt "Select an NGW100 add-on board to support"
+	default BOARD_ATNGW100_ADDON_NONE
+
+config BOARD_ATNGW100_ADDON_NONE
+	bool "None"
+
 config BOARD_ATNGW100_EVKLCD10X
-	bool "Add support for EVKLCD10X addon board"
+	bool "EVKLCD10X addon board"
 	help
 	  This enables support for the EVKLCD100 (QVGA) or EVKLCD101 (VGA)
 	  addon board for the NGW100. By enabling this the LCD controller and
@@ -14,7 +21,7 @@ config BOARD_ATNGW100_EVKLCD10X
 	  The MCI pins can be reenabled by editing the "add device function" but
 	  this may break the setup for other displays that use these pins.
 
-	  Choose 'Y' here if you have a EVKLCD100/101 connected to the NGW100.
+endchoice
 
 choice
 	prompt "LCD panel resolution on EVKLCD10X"