netfilter: xtables: add missing depends for xt_TEE

Aviod these link-time errors when IPV6=m, XT_TEE=y:

net/built-in.o: In function `tee_tg_route6':
xt_TEE.c:(.text+0x45ca5): undefined reference to `ip6_route_output'
net/built-in.o: In function `tee_tg6':
xt_TEE.c:(.text+0x45d79): undefined reference to `ip6_local_out'
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/Kconfig

@@ -505,6 +505,7 @@ config NETFILTER_XT_TARGET_RATEEST
 config NETFILTER_XT_TARGET_TEE
 	tristate '"TEE" - packet cloning to alternate destiantion'
 	depends on NETFILTER_ADVANCED
+	depends on (IPV6 || IPV6=n)
 	---help---
 	This option adds a "TEE" target with which a packet can be cloned and
 	this clone be rerouted to another nexthop.