python-xml depends on python-elementtree as the latter just contains a C library
used by the former. However there's no point to this split apart from
increasing the number of packages, so merge -elementtree into python-xml.
(From OE-Core rev: 5f7206eba3953b7f29148ecfb791995773ee5fc7)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>