[alert_handler] Duplicate escalation counter
[alert_handler] Duplicate escalation counter

These counters are duplicated to harden the design against FI attacks.
In case the counters have an inconsistent state, the escalation FSM
goes into a terminal error state in which all countermeasures are asserted
simultaneously.

Signed-off-by: Michael Schaffner <a005a2d3342a687ea2d05360c953107acbe83e08@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan