samples: update to not use // download

Parallel download can cause issues in some network environments
(eg. behind some firewalls/routers), so default to not //.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 reporter_name="Julien DUSSER"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-10/msg00054.html"

 reporter_comment="Soft-float for the 405 PowerPC"