[Linaro-validation] tcpanda auto builders going offline

The Validation lab is shifting to a new location this week so I've started a graceful shutdown of the tcpanda boards. Merge requests will continue to queue and run on x86 but will back up until the lab comes online at the end of this week. If the backlog gets too big then I'll re-enable an ursa board or two.

Please work as normal but expect the builds results to take longer to come through.

-- Michael