fix build script for v3.9-rc1

arm introduced multiplatorm aka device-tree support. This requires
an additional make variable being specified on the command line to
create the uImage. Also changes sudo to fakeroot which allows to
build panda images on xlinux.

Cc: Piotr Haber <phaber@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Add association check to loadmod script

Association check could make sure dhcp only carried out on associated interface.