v2021: dpkg-exclusions: Split exclusion between docs and minimal specific

Picking 1453ad4f for v2021. This should fix connman test failure in v2021, see https://phabricator.apertis.org/T8261

The dpkg exclusions are too broad for the HMI image. Fox example, zoneinfo (tzdata pkg) is required in HMI, while it's fine to remove from minimal image, which just runs in UTC.

This commit splits the overlay, with all kind of docs excluded everywhere and the rest only on minimal image.