samus: Add define for EVT2 board
samus: Add define for EVT2 board

EVT2 will be board id 0b100.

BUG=chrome-os-partner:32359
BRANCH=samus
TEST=make buildall

Signed-off-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/220258
Reviewed-by: Alec Berg <alecaberg@chromium.org>
(cherry picked from commit 08e0421359d50272d7d1e544aa5e6d222aae34ef)
Signed-off-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>

Change-Id: Id82c319e84fac6db1a5223692e575bfe11790190
Reviewed-on: https://chromium-review.googlesource.com/221144
Tested-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Reviewed-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Commit-Queue: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>

thehobn/ec,thehobn/ec,thehobn/ec,thehobn/ec