tipc: not enable tipc when ipv6 works as a module

When using ipv6_dev_find() in one module, it requires ipv6 not to
work as a module. Otherwise, this error occurs in build:

  undefined reference to `ipv6_dev_find'.

So fix it by adding "depends on IPV6 || IPV6=n" to tipc/Kconfig,
as it does in sctp/Kconfig.

Fixes: 5a6f6f57 ("tipc: set ub->ifindex for local ipv6 address")
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/Kconfig

@@ -6,6 +6,7 @@
 menuconfig TIPC
 	tristate "The TIPC Protocol"
 	depends on INET
+	depends on IPV6 || IPV6=n
 	help
 	  The Transparent Inter Process Communication (TIPC) protocol is
 	  specially designed for intra cluster communication. This protocol