update hooks: clean out linux-3.4 for all boards

Also update the previous hook that cleaned out the kernel (slowly)
from specific boards to use this new one.

BUG=chromium:514682
TEST=precq passes
CQ-DEPEND=CL:298220

Change-Id: I486e05af109732a559eba67d80bc5e168134b1e5
Reviewed-on: https://chromium-review.googlesource.com/298430
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Ben Zhang <benzh@chromium.org>
Reviewed-by: Haixia Shi <hshi@chromium.org>
3 files changed