ade: Add fallback to detect release and arch information

Tool ade needs to find out release and distribution information for SDK and sysroots. This was previously done reading /etc/image_version but this custom file was dropped in favor of /etc/os-release.

A similar issue is found when trying to detect sysroot's architecture since pkg-config.multiarch is no longer supported.

infrastructure/apertis-issues#329 (closed)

Signed-off-by: Walter Lozano walter.lozano@collabora.com