Add new test cases to check devices and update the exist test cases
to be consistent.

Several new cases are added to check devices:
* rtc
* watchdog
* virtiorng

Update the exist test cases on:
* Adding wget to check network connection
* Adjusting the running order in SMP tests
* Updating the messages to be consistent

The recipe bb file is updated to install these new added cases.

Issue-Id: SCM-4872
Signed-off-by: Robbie Cao <robbie.cao@arm.com>
Change-Id: I23baa6f405a392f4a49d2f6f827cc644a04a28a9
Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>