Upgrade OpenVSwitch to version 2.5.0 to support kernels up to 4.3

Most patches for 4.1 are no longer needed, only a minor patch to fix a
missing WAIT_ANY constant. 2.5.0 depends on nf_conntrack (ipv4 and ipv6)

Signed-off-by: Jeroen van Bemmel <jvb127@gmail.com>

net/openvswitch/patches/0009-fix-test-ovn.patch

@@ -0,0 +1,11 @@
+--- a/tests/test-ovn.c
++++ b/tests/test-ovn.c
+@@ -1043,7 +1043,7 @@ wait_pid(pid_t *pids, int *n)
+     int status;
+     pid_t pid;
+ 
+-    pid = waitpid(WAIT_ANY, &status, 0);
++    pid = waitpid(-1, &status, 0);
+     if (pid < 0) {
+         ovs_fatal(errno, "waitpid failed");
+     } else if (WIFEXITED(status)) {