The DSL-2740B/DSL-2741B rev C2 support was missing the board definition,
resulting in a kernel panic on boot.
This patch adds it, and also renames the generated image name to properly
reflect that it is for the revision C2, and for both the DSL-2740B and
DSL-2741B.
Signed-off-by: Jonas Gorski <jonas.gorski+openwrt@gmail.com>
SVN-Revision: 24188
