[AVR32] Board code for ATNGW100

Add board code and defconfig for the ATNGW100 Network Gateway kit.
For more information about this board, see

http://www.atmel.com/dyn/products/tools_card.asp?tool_id=4102

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 7a1eb44..50fee54 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -111,6 +111,9 @@
 config BOARD_ATSTK1000
 	bool "ATSTK1000 evaluation board"
 	select BOARD_ATSTK1002 if CPU_AT32AP7000
+
+config BOARD_ATNGW100
+	bool "ATNGW100 Network Gateway"
 endchoice
 
 choice