feat(realm): add tests for min, max and default  MECID

This patch introduces two tests. Each one assigns the minimum and
maximum MECID to a newly created Realm respectively. In addition
a third test assigns the default MECID (0) to two realms to test
the shared state of this MECID by default.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: I0498084f9c808b6d4db16a939495635c394b2ff3
2 files changed