[keymgr] Latch async faults such that they are permanent
[keymgr] Latch async faults such that they are permanent

- Fixes #8187

Signed-off-by: Timothy Chen <d7b2ae30d8c0f215facd721941273067fd1d14a2@google.com>

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