Make ALERT_TEST transient

[rivos-eblot]

ALERT_TEST registers (in all OT IPs) generate an edge signal, i.e. signal the Alert Handler and automatically returns to their stable, idle state.

This behavior was not known by the time these registers have been implemented in QEMU, and behave as bi-stable registers, i.e. stay high once they have been triggered. This should be fixed in most IPs.