netfilter: default CONFIG_NETFILTER_INGRESS to y

Useful to compile-test all options.
Suggested-by: Alexei Stavoroitov <ast@plumgrid.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/Kconfig

@@ -3,6 +3,7 @@ menu "Core Netfilter Configuration"
 
 config NETFILTER_INGRESS
 	bool "Netfilter ingress support"
+	default y
 	select NET_INGRESS
 	help
 	  This allows you to classify packets from ingress using the Netfilter