Add a dummy flag to fix buildbot failure
Add a dummy flag to fix buildbot failure

BUG=chrome-os-partner:5177
TEST=./build_image -h | grep crosbug12352_arm_kernel_signing

Change-Id: Id61889f4e16ed7e4e774c00c3cb886811c5ccfd7
Reviewed-on: http://gerrit.chromium.org/gerrit/4805
Reviewed-by: Che-Liang Chiou <57969107b634cf11cb64e9d768fd46929066adab@chromium.org>
Tested-by: Che-Liang Chiou <57969107b634cf11cb64e9d768fd46929066adab@chromium.org>

crawford/scripts,andrejro/coreos--scripts,smilart/scripts,zhang0137/scripts,glevand/coreos--scripts,marineam/coreos-scripts,trnubo/scripts,BugRoger/scripts,marineam/coreos-scripts,nicescale/scripts,endocode/scripts,fivethreeo/scripts,vmware/coreos-scripts,fivethreeo/scripts,smilart/scripts,fivethreeo/scripts,zhang0137/scripts,crawford/scripts,trnubo/scripts,nicescale/scripts,mjg59/scripts,marineam/coreos-scripts,coreos/scripts,coreos/scripts,trnubo/scripts,bcwaldon/coreos-scripts,mischief/scripts,glevand/coreos--scripts,vmware/coreos-scripts,sigma/coreos-scripts,BugRoger/scripts,vmware/coreos-scripts,mischief/scripts,mischief/scripts,gtank/scripts,bcwaldon/coreos-scripts,endocode/scripts,bcwaldon/coreos-scripts,mjg59/scripts,endocode/scripts,smilart/scripts,sigma/coreos-scripts,andrejro/coreos--scripts,BugRoger/scripts,gtank/scripts,crawford/scripts,nicescale/scripts,gtank/scripts,mjg59/scripts,sigma/coreos-scripts,zhang0137/scripts,andrejro/coreos--scripts