test: Add vboot_evil implementation

Add a library which performs two different attacks on a FIT.

Signed-off-by: Julien Lenoir <julien.lenoir@intel.com>
Signed-off-by: Bruce Monroe <bruce.monroe@intel.com>
Signed-off-by: Arie Haenel <arie.haenel@intel.com>
Signed-off-by: Simon Glass <sjg@chromium.org>