fngsystem: Add uuu scripts to release artifacts
This MR is a fix for the last issue reported by SECO for [746-001617] uuu-scripts for Nallino not working task: https://secogroup.atlassian.net/browse/YT-83?focusedCommentId=45627
It addresses a following problem: although the uuu scripts and other auxiliary files, which are needed to boot iMX6 boards, are built when a fngsystem image is built, these files are not included into release delivery.
Add DISTRO_RELEASE_ARTEFACTS
for mx6/mx6ull machines to fix this.
Edited by Dmitry Petrov