The ad799x driver moved out of staging since kernel 3.16, so update filepath, config elements and description. Signed-off-by: Hartmut Knaack <knaack.h@gmx.de> git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42524 3c298f89-4303-0410-b956-a3cf2f4a3e73