Add a bunch of missing "zephyr/" prefixes to #include statements in
various test and test framework files.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
As Zephyr currently requires CMake version 3.20.0, update all
occurrences of cmake_minimum_required.
Signed-off-by: Reto Schneider <reto.schneider@husqvarnagroup.com>