vboot: remove workaround in diagnostics UI

The cr50 has been changed to report live status of the power button so
this workaround is no longer needed.

TEST=Locally built and flashed onto system with modified cr50.  Verified
that power button status is read and works reliably.

Change-Id: Ia9b33610c897085e79dd18805350c41e17e3d9f2
Signed-off-by: Matt Delco <delco@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1534621
Commit-Ready: Matt Delco <delco@chromium.org>
Tested-by: Matt Delco <delco@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
1 file changed