package/wf111: do a direct download

We can now do a download without prior registration, so we can drop the
requirement for a local, pre-downloaded tarball, now.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Julien CORJON <corjon.j@ecagroup.com>
Cc: Antoine Ténart <antoine.tenart@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>