If CONFIG_DRIVER_WEXT=y is not used in .config, but driver_wext.c gets pull in to help another driver wrapper, rfkill code needs to included to fix the build.
@@ -154,6 +154,7 @@ endif
ifdef CONFIG_WIRELESS_EXTENSION
DRV_WPA_CFLAGS += -DCONFIG_WIRELESS_EXTENSION
DRV_WPA_OBJS += ../src/drivers/driver_wext.o
+NEED_RFKILL=y
endif
ifdef NEED_NETLINK