vboot2: Add sd->fw_version_secdata field to communicate to crossystem

Partial backport of Change-Id:
I2a0c3e51b158a35ac129d2abce19b40c6c6381a6.

This patchs adds a new vb2_shared_data field to store the current
rollback prevention version number stored in secdata (TPM). This
information needs to be retrieved from there by coreboot (current
hack) or vboot2 kernel verification (bright shiny future) so it can be
passed along to the operating system and user space.

BRANCH=none
BUG=chrome-os-partner:35941
TEST=Manual on Kitty. Boot in recovery mode, verify that fwver shows
correct non-zero value.

Change-Id: Ibc9ea75727689549c65e908504d62e90ae1da3c9
Reviewed-on: https://chromium-review.googlesource.com/245534
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: Shawn N <shawnn@chromium.org>
4 files changed