Since tasks were renamed to packagegroups some time ago, this variable
name implies that its usage is necessarily related to them which is not
the case. Rename the variable to more closely represent what it does
(whilst still providing backwards-compatibility with a warning for
PACKAGE_GROUP).
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
