package/network-manager: add patches to build with kernel headers 3.2

package/network-manager: add patches to build with kernel headers 3.2

+ lower kernel headers dependency

According to upstream [1], there is no known minimal kernel-version, nor
minimal required feature-set.

Experimentally tested, that 1.0.2 is works with 3.2 kernel headers, even
some features will be missing [2].

[1] https://mail.gnome.org/archives/networkmanager-list/2015-April/msg00039.html
[2] https://mail.gnome.org/archives/networkmanager-list/2015-April/msg00041.html

[Thomas: add comment in Config.in to indicate that it may work with
earlier kernel versions.]

Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>