The value of tmnxCardLastBootupReason indicates the type of the last
reboot/reset of the IOM card.
Not all reasons exist in all software versions.
hardReboot - new/different card inserted for first time
softReset - user initiated soft reset
powerCycle - user initiated power cycle
clearCard - user initiated clear card
activitySwitch - card rebooted during activity switch
configChange - configuration change forced a reboot
runtimeFail - card failed while running and was rebooted
bootFail - card failed during boot and was rebooted
unexpected - card unexpectedly rebooted
issuTimeout - ISSU timeout timer expired
reinserted - card was removed and reinserted
issuHardReboot - card rebooted during ISSU upgrade
(soft reset ineligible)
ccmFail - Chassis Control Module (CCM) failed.