mainboards: Add CHROMEOS_VBNV_* where appropriate

For boards with MAINBOARD_HAS_CHROMEOS, we should also
state what kind of storage is available for vboot's
non-volatile data.

The flags are taken from the chromium repository and
have no effect with CHROMEOS disabled.

Change-Id: I1747ad26c8c7f6d4076740ec2800dbd52c5d6b3d
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/9952
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
24 files changed