zmake: remove unit tests that were moved to platform/ec

This change deletes the python unit tests for zmake that now exist in
platform/ec.

BUG=b:177003034
TEST=zmake -l INFO testall (see that these tests are still run in
     platform/ec)

Change-Id: I041ae130838446b65d434c8d3ac96a83cc594710
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2623749
Tested-by: Yuval Peress <peress@chromium.org>
Auto-Submit: Yuval Peress <peress@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
2 files changed