If what @gtj proposed doesn’t work out, some users also reported improvement in similar cases adding pci=nomsi to kernel boot args.
As you are using a custom board, not sure but you may also have a look to this topic.
If this doesn’t work, you may get rid of kernel messages with pci=noaer, but this wouldn’t fix the errors (these are reported as corrected, though), but only disable errors reporting so that it doesn’t spend time filling your kernel log files.