Make the cmake tests work with a namespace build.

Make the cmake tests work with a namespace build.

Change-Id: I6858c324548373c57963b5ef137772a1f780ec78
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>
Reviewed-by: Clinton Stimpson <clinton@elemtech.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>