Test: Add build config which support level 3 isolation

Before this change only the core test suit was executed with level 3
isolation. From now regression test cases which compliant with
TFM_LVL 3 isolation can be executed with this setting.

Change-Id: Iddc376384583590cef4e47209b779f55d73ff41b
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
9 files changed