lantiq BTHOMEHUBV2B - update dts for automatic detection of ubi partition and rootfs type

This patches the BTHOMEHUB2B device tree to make use of the
new code for automatic detection of the ubi partition and the
rootfs type within it. Gets rid of the ugly alternative bootargs
lines.

Signed-off-by: Ben Mulvihill <ben.mulvihill@gmail.com>
Acked-by: Daniel Golle <daniel@makrotopia.org>

SVN-Revision: 41214