How do I disable the changing of the MAC address after each reboot for the IG60 and 60-SOM DVK running off an SD card with Laird Linux

You need to boot into Linux and after Login log in issue the command

fw_setenv ethaddr <desired MAC address> 

for example:

fw_setenv ethaddr AABBCCDDEEFF

and reboot

You can read out the address previously set with:

fw_printenv ethaddr