automation: use expect to run QEMU

automation: use expect to run QEMU

Use expect to invoke QEMU so that we can terminate the test as soon as
we get the right string in the output instead of waiting until the
final timeout.

For timeout, instead of an hardcoding the value, use a Gitlab CI
variable "QEMU_TIMEOUT" that can be changed depending on the latest
status of the Gitlab CI runners.

[This backport skips the PPC and RISC scripts as well as the XTF
scripts on x86]

Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
master commit: c36efb7fcea6ef9f31a20e60ec79ed3ae293feee
master date: 2024-08-09 23:59:20 -0700