Remove the cmake/ directory

zmake now references the copy in platform/ec/zephyr

BUG=b:177609422
TEST=CQ

Change-Id: I7a2a6ac10e20d5007275e5e7d7ec6c7bbb080463
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2633887
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Simon Glass <sjg@chromium.org>
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Auto-Submit: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
16 files changed