ci: Modify lava tests scripts for Corstone-1000 MPS3

Due to the slow performance of the MPS3 boards running the latest software we have to modify the test scripts in a number of ways. The first is to provide the string the should be looked for to ensure the kernel has started so the timeouts can start from the correct point. The second to to increase the connection timeouts for the login actions so that long running scripts can be run in loops where the prompt wouldn't be seen for long time periods. The final change is to monitor the status of the networking subsystem and restart it if timeouts in the kernel status messaging occur causing it to enter a failed state and restart it if needed. Changes have been applied to both tests to keep them in sync.

Changelog: bug Signed-off-by: Drew Reed Drew.Reed@arm.com