[NETFILTER]: Fix CONNMARK Kconfig dependency

Connection mark tracking support is one of the feature in connection
tracking, so IP_NF_CONNTRACK_MARK depends on IP_NF_CONNTRACK.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index fd2eb5d..30aa8e2 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -34,6 +34,7 @@
 
 config IP_NF_CONNTRACK_MARK
 	bool  'Connection mark tracking support'
+	depends on IP_NF_CONNTRACK
 	help
 	  This option enables support for connection marks, used by the
 	  `CONNMARK' target and `connmark' match. Similar to the mark value