host/lib/flashrom: enable --fast-verify for write operations

We caused a boot-speed regression as we are currently verifying the
entire flash chip after any write.

Flashrom has an option --fast-verify which verifies only the region
written, which is significantly faster.  It also looks like this is
the way mosys used to handle flashrom writes, so we can align with the
old behavior this way.

BUG=chromium:1091903
BRANCH=none
TEST=unit tests, and boot speed regression went away (on octopus)

Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Change-Id: If8d2288cb0c08e8644b6e05f7b174c3c21542f94
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2242738
Reviewed-by: Joel Kitching <kitching@chromium.org>
2 files changed