ar71xx: add profile and build image fot the TL-WA830RE v1 board

Added support for the TP-LINK TL-WA830RE v1 Range Extender.
Based on the WA901ND v1 support. Hardware IDs checked against
original firmware. Patch was successfully tested on hardware.

Signed-off-by: Ronald Hecht <ronald.hecht@gmx.de>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 35789