netfilter: fix Kconfig dependencies

Fix dependencies of netfilter realm match: it depends on NET_CLS_ROUTE,
which itself depends on NET_SCHED; this dependency is missing from netfilter.

Since matching on realms is also useful without having NET_SCHED enabled and
the option really only controls whether the tclassid member is included in
route and dst entries, rename the config option to IP_ROUTE_CLASSID and move
it outside of traffic scheduling context to get rid of the NET_SCHED dependeny.

Reported-by: Vladis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 9e95d7f..dcb2e18 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -140,6 +140,9 @@
 	  handled by the klogd daemon which is responsible for kernel messages
 	  ("man klogd").
 
+config IP_ROUTE_CLASSID
+	bool
+
 config IP_PNP
 	bool "IP: kernel level autoconfiguration"
 	help
@@ -655,4 +658,3 @@
 	  on the Internet.
 
 	  If unsure, say N.
-