samus_pd: Add BST_DISABLE GPIO for EVT2 board
samus_pd: Add BST_DISABLE GPIO for EVT2 board

This pin is already set to out+low so it should be fine to rename
it on EVT1 boards.

BUG=chrome-os-partner:32031,chrome-os-partner:32359
BRANCH=samus
TEST=make buildall

Signed-off-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/220259
Reviewed-by: Alec Berg <alecaberg@chromium.org>
(cherry picked from commit af3d103dbc3ddbb6004240186a946efe1cc8b8f4)
Signed-off-by: Duncan Laurie <70662b43bc1a20b57ded72a2b08be88dd0da4841@chromium.org>

Change-Id: I0d904b0301b793bbfa1d829b4fce60e0b1154b00
Reviewed-on: https://chromium-review.googlesource.com/221145
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