Separate shutdown and stats after shutdown tests

Creating new test suite for System shutdown and stats after shutdown
tests separate from the other manual tests since the others have been
automated for some platforms.  This test suite is intended to be used
for manual testing for the upcoming release.

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: I3725b28528696fa51d4c1f3af60f8a6e61e1a702