Kconfig: Add new config for OVERRIDE_DEVICETREE

This change adds a new config option OVERRIDE_DEVICETREE that allows
variants to provide an override devicetree file to override the
registers and/or add new devices on top of the ones provided by
baseboard devicetree using CONFIG_DEVICETREE.

BUG=b:80081934

Change-Id: Ica046b7e0d70d0f1e8d94da714d1e62032277916
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/26691
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed