nl80211: Include linux/rtnetlink.h explicitly

This is needed with libnl-tiny to get various definitions that
get included implicitly with libnl.

src/drivers/driver_nl80211.c

@@ -22,6 +22,7 @@
 #include <netlink/genl/genl.h>
 #include <netlink/genl/family.h>
 #include <netlink/genl/ctrl.h>
+#include <linux/rtnetlink.h>
 #include <netpacket/packet.h>
 #include <linux/filter.h>
 #include "nl80211_copy.h"

src/drivers/netlink.h

@@ -16,6 +16,7 @@
 #define NETLINK_H
 
 struct netlink_data;
+struct ifinfomsg;
 
 struct netlink_config {
 	void *ctx;