Include <sys/types.h> to get the u_int* definitions

This is needed to fix the build with the musl C library, and this
patch comes from
http://git.alpinelinux.org/cgit/aports/plain/main/libnfnetlink/musl-fix-includes.patch.

It will no longer be needed with upcoming upstream releases of
libnfnetlink, since they have switched to use the <stdint.h> types
instead. However this change was too invasive to backport.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

--- libnfnetlink-1.0.1.orig/include/libnfnetlink/linux_nfnetlink.h
+++ libnfnetlink-1.0.1/include/libnfnetlink/linux_nfnetlink.h
@@ -1,6 +1,6 @@
 #ifndef _NFNETLINK_H
 #define _NFNETLINK_H
-#include <linux/types.h>
+#include <sys/types.h>
 #include <libnfnetlink/linux_nfnetlink_compat.h>
 
 enum nfnetlink_groups {
--- libnfnetlink-1.0.1.orig/include/libnfnetlink/libnfnetlink.h
+++ libnfnetlink-1.0.1/include/libnfnetlink/libnfnetlink.h
@@ -15,6 +15,7 @@
 #define aligned_u64 unsigned long long __attribute__((aligned(8)))
 #endif
 
+#include <sys/types.h>
 #include <sys/socket.h>	/* for sa_family_t */
 #include <linux/netlink.h>
 #include <libnfnetlink/linux_nfnetlink.h>