Document the board and how to flash coreboot.
Change-Id: Id585b064054b338ea8cead6edb6c5153030b9cde
Signed-off-by: Alicja Michalska <alicja.michalska@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85680
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>
