- hide atmel target if arch is not arm nor avr32

target/device/Atmel/Config.in

@@ -1,5 +1,9 @@
-menu "Atmel Target"
+menuconfig BR2_TARGET_ATMEL
+	bool "Atmel Target"
+	depends on BR2_arm || BR2_avr32
+	default n
 
+if BR2_TARGET_ATMEL
 comment "Add Atmel Target here"
 
-endmenu
+endif