Some hAP lite routers aren't detected because
/proc/cpuinfo shows "RouterBOARD RB941-2nD"
instead of "RouterBOARD 941-2nD".

Fix that.

Signed-off-by: Julien Rabier <taziden@flexiden.org>
[Alter string to include all flavours + slight rewrite of commit msg]
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>