netfilter: fix kconfig unmet dependency warning

Fix netfilter kconfig unmet dependencies warning & spell out
"compatible" while there.

warning: (IP_NF_TARGET_TTL && NET && INET && NETFILTER && IP_NF_IPTABLES && NETFILTER_ADVANCED || IP6_NF_TARGET_HL && NET && INET && IPV6 && NETFILTER && IP6_NF_IPTABLES && NETFILTER_ADVANCED) selects NETFILTER_XT_TARGET_HL which has unmet direct dependencies ((IP_NF_MANGLE || IP6_NF_MANGLE) && NETFILTER_ADVANCED)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>