dtc: fix project and download url

This fix the error:

fatal: unable to connect to git.jdl.com:
git.jdl.com[0: 208.123.73.151]: errno=Connection refused

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>