MAINTAINER: add bridge netfilter

So scripts/get_maintainer.pl shows the Netfilter mailing lists.
Reported-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

MAINTAINERS

@@ -6996,6 +6996,7 @@ F:	include/uapi/linux/netfilter/
 F:	net/*/netfilter.c
 F:	net/*/netfilter/
 F:	net/netfilter/
+F:	net/bridge/br_netfilter*.c
 
 NETLABEL
 M:	Paul Moore <paul@paul-moore.com>