enable IP_ADVANCED_ROUTER for busybox 'ip rule show'

Adding this config option allows the user who has enabled the feature
CONFIG_FEATURE_IP_RULE in busybox to see the various routing table
prio's and set/change them with 'ip route ... table ...' and 'ip rule'.

Signed-off-by: Jason <github@lakedaemon.net>

arch/arm/configs/cyanogen_mahimahi_defconfig

@@ -473,8 +473,13 @@ CONFIG_NET_KEY=y
 # CONFIG_NET_KEY_MIGRATE is not set
 CONFIG_INET=y
 # CONFIG_IP_MULTICAST is not set
-# CONFIG_IP_ADVANCED_ROUTER is not set
+CONFIG_IP_ADVANCED_ROUTER=y
+CONFIG_ASK_IP_FIB_HASH=y
+# CONFIG_IP_FIB_TRIE is not set
 CONFIG_IP_FIB_HASH=y
+CONFIG_IP_MULTIPLE_TABLES=y
+# CONFIG_IP_ROUTE_MULTIPATH is not set
+# CONFIG_IP_ROUTE_VERBOSE is not set
 # CONFIG_IP_PNP is not set
 # CONFIG_NET_IPIP is not set
 # CONFIG_NET_IPGRE is not set