Drop eventlog support from mosys

All clients migrated to use elogtool, we can delete the command from
mosys now.

BUG=b:203777035
TEST=compiles

Change-Id: I603ed79d5aa48f134ca0bd15471b659ed45a793a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/mosys/+/3249305
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Auto-Submit: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
27 files changed