vboot2: Move old struct handling to lib20/

This is part 4 of a series of changes to rearrange the vboot2 library
so that it's possible to start using the new-style data structs.  This
change moves knowledge of the old vboot1 data structs into lib20; 2lib
now contains only code which is common to both vboot2.x libraries
(that is, code which is data structure version agnostic).

No functional changes; just rearranging code and tests.

BUG=chromium:423882
BRANCH=none
TEST=make runtests && VBOOT2=1 make runtests (works with/withoug VBOOT2 flag)
     And compile firmware for veyron_pinky
CQ-DEPEND=CL:233051

Change-Id: I8f9e67157575e5be14952ef4809c3dfafd92596d
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/233021
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
26 files changed