buildroot

iproute2: bump to version 4.12.0

Drop upstream patch.

Add uClibc-ng compatibility fix. This is needed due to missing definition in
netinet/in.h.

Add license file hash.

Cc: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>