These test vectors include the k value, so we can get a deterministic
test.

Change-Id: Ie3cb61a99203cd55b01f4835be7c32043309748d
Reviewed-on: https://boringssl-review.googlesource.com/10701
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>