Why mcelogd fails to start with "AMD Processor family XX: Please load edac_mce_amd module. CPU is unsupported"?

Issue

• mcelogd fails to start with:

[root@example]# /etc/init.d/mcelogd start
Starting mcelog daemon                                     [FAILED]
AMD Processor family 16: Please load edac_mce_amd module.
CPU is unsupported

• mcelog.service fails to start with:

* mcelog.service - Machine Check Exception Logging Daemon
   Loaded: loaded (/usr/lib/systemd/system/mcelog.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2020-06-03 18:17:30 HST; 14min ago
  Process: 3320 ExecStart=/usr/sbin/mcelog --ignorenodev --daemon --foreground (code=exited, status=1/FAILURE)
 Main PID: 3320 (code=exited, status=1/FAILURE)

Jun 03 18:17:30 generic systemd[1]: Started Machine Check Exception Logging Daemon.
Jun 03 18:17:30 generic mcelog[3320]: mcelog: ERROR: AMD Processor family 23: mcelog does not support this processor.  Please use the edac_mce_amd module instead.
Jun 03 18:17:30 generic mcelog[3320]: CPU is unsupported
Jun 03 18:17:30 generic systemd[1]: mcelog.service: Main process exited, code=exited, status=1/FAILURE
Jun 03 18:17:30 generic systemd[1]: mcelog.service: Failed with result 'exit-code'.