netfilter: fix several Kconfig problems in NF_LOG_*

warning: (NETFILTER_XT_TARGET_LOG) selects NF_LOG_IPV6 which has unmet direct dependencies (NET && INET && IPV6 && NETFILTER && IP6_NF_IPTABLES && NETFILTER_ADVANCED)
warning: (NF_LOG_IPV4 && NF_LOG_IPV6) selects NF_LOG_COMMON which has unmet direct dependencies (NET && INET && NETFILTER && NF_CONNTRACK)

Fixes: 83e96d44 ("netfilter: log: split family specific code to nf_log_{ip,ip6,common}.c files")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>