libreboot-utils: Add cbmem
The cbmem utility enables to retrieve the Coreboot and Libreboot boot
logs. This requires Coreboot or Libreboot to be built with
CONFIG_CONSOLE_CBMEM=y to work.
In addition cbmem also supports retrieving additional boot information
like timestamps (which requires CONFIG_COLLECT_TIMESTAMPS=y), and so
on.
GRUB also has a cbmem console, so if configured to use it we can also
retrieve the GRUB boot log.
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>