ramips: fix Argus ATP-52B board and image names

The following patch:
 * changes board name from "argus-atp52b" to "atp-52b"
 * changes dts filename
 * fixes LED names in dts file and base-files scripts
 * removes manufacturer name from image filename

for Argus ATP-52B device.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46621 3c298f89-4303-0410-b956-a3cf2f4a3e73