data build_sd.sh: add "--add-wifi" command line option

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
data build_sd.sh: kernel images update

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Merge branch 'master' of https://github.com/cosino/cosino.github.io

Conflicts:
	data/build_sd.sh