'package-management' allows to install packages in runtime. This feature is not
usually utilize by customers so we are removing this support from all images.
Signed-off-by: Tatiana Leon <Tatiana.Leon@digi.com>
This variable and all its references were removed in Yocto 2.4
https://jira.digi.com/browse/DEL-5518
Signed-off-by: Jose Diaz de Grenu <Jose.DiazdeGrenu@digi.com>