feat(lib/s2tt): add device memory tests

- Add device memory related unit tests.
- Modify s2tte_get_ripas_tc2() and create
new s2tte_get_ripas_tc3() test to consider
RMI_ASSIGNED_DEV HIPAS value.

Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
Change-Id: I670458bb4425f3b130e4b7c056ce3d5ec856f4b2
10 files changed