lantiq: configure uboot-envtools on BTHOMEHUBV2B and make it work correctly on other lantiq boards

Generate the configuration file for uboot-envtools
on BTHOMEHUBV2B. Adds the specific parameters for the
BTHOMEHUBV2B and also fixes an incorrect path which
would have affected other lantiq boards as well
(currently only the GIGASX76X).

Signed-off-by: Ben Mulvihill <ben.mulvihill@gmail.com>

SVN-Revision: 41597