linux-headers: drop

These have been moved to the chromiumos-overlay; drop this copy to keep
from confusing people.

BUG=chromium:478599
TEST=precq passes

Change-Id: I80e7f02206d001544d3434dbcf9316164d87e703
Reviewed-on: https://chromium-review.googlesource.com/267060
Reviewed-by: Heng-ruey Hsu <henryhsu@google.com>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
3 files changed