connman: add patch to fix build with headers >= 4.5

connman: add patch to fix build with headers >= 4.5

Add a patch from Gentoo that fixes the build on linux headers >= 4.5
The probem arises from an incompatibility in newer headers when both
net/if.h and linux/if.h are included in the same source.
See https://bugs.gentoo.org/show_bug.cgi?id=577584

Fixes:
http://autobuild.buildroot.net/results/48e/48e6f34a7940f52d987db47784c0d9e82f39de7c/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>