ipv6 addrconf: extend ifa_flags to u32

There is no more space in u8 ifa_flags. So do what davem suffested and
add another netlink attr called IFA_FLAGS for carry more flags.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Thomas Haller <thaller@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 76d5427..b58c36c 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -50,8 +50,8 @@
 
 	int			state;
 
+	__u32			flags;
 	__u8			dad_probes;
-	__u8			flags;
 
 	__u16			scope;