bmpblk/zork: Reduce dpi to 96

To avoid insufficient RO space for the upcoming error strings
(CL:2623537), reduce dpi to 96 for berknip (zork).

Since zork has locked down its RO, there is no need to cherry-pick this
CL to the firmware branch.

BUG=b:144969091
TEST=make BOARD=zork
BRANCH=none

Change-Id: I89cdcae260546572abfc37dc7427aa7dfa000ed8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/bmpblk/+/2708988
Tested-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-by: Joel Kitching <kitching@chromium.org>
Commit-Queue: Yu-Ping Wu <yupingso@chromium.org>
diff --git a/boards.yaml b/boards.yaml
index b4caa4a..62ca05c 100644
--- a/boards.yaml
+++ b/boards.yaml
@@ -307,6 +307,7 @@
 zork:
   # 1920x1080, boots recovery image on any SD card or USB ports.
   screen:   [1920, 1080]
+  dpi: 96  # DO NOT COPY-PASTE -- follow instructions at top of file.
 
 dedede:
   # 2400x1600, boots recovery image on USB ports.