-There are some cleanup targets we would like to explain.
-"make clean" will only clean the firmware images and the root
-filesystem. "make dirclean" will remove the extracted kernel source
-and all exctracted software. (busybox,bridge-utils,..), but will
-preserve your toolchain. (compiler,linker,..)
-"make distclean" will remove everything, including the toolchain,
-all downloaded source code archives and your firmware configuration.
-You can cleanup separate directories by using "make application-dirclean"
-and rebuild the firmware with "make".