package/connman: version bump to 1.12, and fix build with newer kernels headers

... while keeping compatibility with older ones.

Fixes autobuild failure:
http://autobuild.buildroot.org/results/f99ae7af46c70f7c356b7771321511a42eb3694d/



Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>