bmpblk: add volteer board Add volteer to the list of boards. BUG=b:142961277 BRANCH=master TEST=none Change-Id: I7fcad704cf7c96601909e7516fd92dccce52662f Signed-off-by: Nick Vaccaro <[email protected]> Reviewed-on: https://chromium-review.googlesource.com/1895272 Legacy-Commit-Queue: Commit Bot <[email protected]> Reviewed-by: Shelley Chen <[email protected]> Reviewed-by: Furquan Shaikh <[email protected]>