OWNERS: drop people no longer working on CrOS

BUG=None
TEST=None

Change-Id: I21165ceb467c3a6cdd5a8c6539f1352576d07ab2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/libevstate/+/5515298
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Sean O'Brien <seobrien@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>