I am facing the same as describe in above link. I am not able to create "/dev/caam-keygen" node. I am working on kernel version 5.4.3 but I tried with kernel version 5.4.80 but still facing the same issue. I am attaching kernel configuration for your reference.
Another thing I wanted to know that which device driver file is responsible to create "/dev/caam-keygen" node?
I have follow the steps successfully and now I wanted to know that How to add support in yocto to create encrypted rootfs so that I can directly flash encrypted rootfs?