refactor(tfut): move config_valid() to utils.sh

config_valid() function had to be moved from build_package.sh to
utils.sh so it can be used in multiple scripts.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Signed-off-by: Edward Potapov <edward.potapov@arm.com>
Change-Id: Ie9fe32eabba047fe8e1e718e06494909d2ac8246
2 files changed