tftf*: Unhandled exception during tests is a test fail-fast

Similar to other fail-fast strings added recently, to prevent failing jobs
to hang until timeout.

Seen at https://tf.validation.linaro.org/scheduler/job/1677111

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I6a9e985f47ad4252b58a74d3b6c8e7022b6fcdcc
3 files changed