[aon_timer,dv] Testplan Update for AON Timer
[aon_timer,dv] Testplan Update for AON Timer

This commit includes updates on the testplan of AON Timer.

Signed-off-by: Canberk Topal <e6b05429a51cc3258c31cb1f7836595b60921a29@lowrisc.org>

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