[IPV6]: Make IPV6_SUBTREES depend on IPV6_MULTIPLE_TABLES.

As IPV6_SUBTREES can't work without IPV6_MULTIPLE_TABLES have IPV6_SUBTREES
depend on it.

Signed-off-by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed