Cherry-pick vboot_reference files from TOT to support crossystem

These files are picked from vboot_reference TOT at this tag:

There's about a dozen individual CLs in TOT which this is coalesced
from.  Rather than attempt to squash all of them, I've just pulled the
current versions.  This admittedly pulls in more files than I'd like
in a single CL.  Most of those are inside the firmware subdir, and are
required for unit tests (esp. load_kernel_test) to compile but aren't
used in the actual OS image.  I have NOT pulled in any unreleated
script changes, such as Gaurav's changes to the signing scripts.

Change-Id: I3521a6eed40ff12c82545f2170090e755d7007fc,,

1. make && make runtests && make clean
2. emerge-x86-alex vboot_reference, then run the resulting crossystem utility on Alex 0053G1+ firmware

Review URL:
26 files changed