eltan/verified_boot: include vboot21 code directly

vboot 2.1 data structures and code, as well as the fwlib21 build
target, are all being deprecated.  Any use of these data
structures and code should be forked and handled separately.
The data structures and functions used by eltan verified boot
were never part of the vboot API, and were never intended to be
used by external parties.

Instead of building fwlib21 target, build fwlib instead, which
will be the only available library going forward.  This can
provide access to the vb2_sha.h API.

Note that vboot 2.1 error codes will also be deprecated in the
future.  At this point, vb2_error_t may also be forked and
included in eltan_vb21.h.

BUG=b:124141368, chromium:968464
TEST=util/abuild/abuild -v -B -e -p none -t FACEBOOK_FBG1701
BRANCH=none

Change-Id: Iae58a0c42161ddfec9908f9867286e3dc1f055a2
Signed-off-by: Joel Kitching <kitching@google.com>
---
M src/vendorcode/eltan/security/include/cb_sha.h
M src/vendorcode/eltan/security/lib/Makefile.inc
M src/vendorcode/eltan/security/verified_boot/Makefile.inc
A src/vendorcode/eltan/security/verified_boot/eltan_vb21.c
A src/vendorcode/eltan/security/verified_boot/eltan_vb21.h
M src/vendorcode/eltan/security/verified_boot/vboot_check.c
6 files changed, 1,113 insertions(+), 32 deletions(-)