oeqa/core/decorator/oetimeout: Add support for OEQA threaded mode
In python signals are only allowed to delivery into the main thread,
to support the threading mode test if the runner is threaded and
use threading.Timer instead.
There are some considerations like SIGALRM interrupts the execution
after N seconds but the Timer only starts a Thread to notice the
timeout and the exception will be raised when the test run ends.
[YOCTO #11450]
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
