dump_vpd_log: Add region to VPD whitelist. BUG=chromium:306527 TEST=run dump_vpd_log --force --stdout and see region being displayed. Change-Id: Ic597cbff9be777064a633a5403e2c3738031fec5 Reviewed-on: https://chromium-review.googlesource.com/172727 Reviewed-by: David Hendricks <[email protected]> Reviewed-by: Yung-chieh Lo <[email protected]> Commit-Queue: Paul Stewart <[email protected]> Tested-by: Paul Stewart <[email protected]>