arm: mvebu: turris_omnia: Implement getting board information from MCU

Implement reading board serial number, first MAC address and board
version from MCU. MCU supports board information if the FEAT_BOARD_INFO
feature bit is set in MCU features.

Prefer getting board information from MCU if supported, fallback to
Atmel SHA chip.

Signed-off-by: Marek BehĂșn <kabel@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
5 files changed