*.elf and *.dat files are provided by package linux-firmware-raspi2 not the kernel. You have an old version installed (3-0ubuntu2~20.04.1 ). Can you update that to the latest version from the archive (6-0ubuntu0~20.04.1):
$ apt update && apt install linux-firmware-raspi2
That version should have support for the new CM4 board.
*.elf and *.dat files are provided by package linux-firmware- raspi2 not the kernel. You have an old version installed (3-0ubuntu2~20.04.1 ). Can you update that to the latest version from the archive (6-0ubuntu0~ 20.04.1) :
$ apt update && apt install linux-firmware- raspi2
That version should have support for the new CM4 board.