Pass the right flags to the tests that create images to ensure valid
usage.
Fixes issue #330
Signed-off-by: James Morrissey <james.morrissey@arm.com>
Co-authored-by: Alessandro Navone <alessandro.navone@arm.com>
Some of the setup functionality is already there in the test harness, so
use that and remove the duplicated code from within the suite.
Signed-off-by: Radek Szymanski <radek.szymanski@arm.com>