Enable overlay

Add the overlay function in the boot script.
The list of overlays can be modified at /boot/overlays.txt on the device.

Change-Id: I388bb5e9450e2bc0fde47dd35768f30efc17acdb
3 files changed
tree: 5be07a6e368fea5bdf61bc7fd344a24c674d33f4
  1. debian/
  2. mt8167-coral/
  3. usr/
  4. boot.txt
  5. overlays.txt
  6. ubootenv.py