Revert "always use .defconfig, otherwise make menuconfig and ADK_APPLIANCE does not work"

This reverts commit f7fb97a8e2160a791487f5a2cd9f744b04cf39bb.

mk/build.mk

@@ -458,7 +458,9 @@ endif
 			|sed -e "s#^config \(.*\)#\1=y#" \
 			>> $(ADK_TOPDIR)/.defconfig; \
 	fi
-	@$(CONFIG)/conf --defconfig=.defconfig $(CONFIG_CONFIG_IN)
+	@if [ ! -z "$(ADK_APPLIANCE)" ];then \
+		$(CONFIG)/conf --defconfig=.defconfig $(CONFIG_CONFIG_IN); \
+	fi
 
 allconfig:
 ifeq (${OStype},Linux)