The CONTRIBUTING.md requests an (or multiple) SPDX identifier for GPL
licenses. But a lot of packages did use a different, non-SPDX style with a
"+" at the end instead of "-or-later".

Signed-off-by: Sven Eckelmann <sven@narfation.org>

Packages such as Perl, Lua, shell scripts don't generate binary files.
Add PKGARCH:=all to them.

Signed-off-by: Deng Qingfang <dengqf6@mail2.sysu.edu.cn>

While an empty led_sysfs definition works as intended (no LED state is
touched), an error message is generated, since the appropriate sysfs
interface does not exist:

          Sat Feb 27 16:42:55 2016 user.err wifitoggle: led:  not found

This patch makes sure that no such error message will be generated.

Signed-off-by: Karol Babioch <karol@babioch.de>

Signed-off-by: Nuno Goncalves <nunojpg@gmail.com>