iproute2: update to 4.17.0

Update to the latest version of iproute2; see https://lwn.net/Articles/756991/
for a full overview of the changes in 4.17.
Remove upstream patch 002-json_print-fix-hidden-64-bit-type-promotion.
Backport upstream patch 001-rdma-sync-some-IP-headers-with-glibc fixing
rdma compile issue.
At the same time re-organize patch numbering so the OpenWRT specific
patches start at 100.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/utils/iproute2/patches/140-keep_libmnl_optional.patch

@@ -0,0 +1,11 @@
+--- a/configure
++++ b/configure
+@@ -281,7 +281,7 @@ check_selinux()
+ 
+ check_mnl()
+ {
+-	if ${PKG_CONFIG} libmnl --exists
++	if [ "${HAVE_MNL}" = "y" ] && ${PKG_CONFIG} libmnl --exists
+ 	then
+ 		echo "HAVE_MNL:=y" >>$CONFIG
+ 		echo "yes"