arndale.conf: enable CONFIG_TUN

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
diff --git a/linaro/configs/arndale.conf b/linaro/configs/arndale.conf
index 3a6c510..cf51e53 100644
--- a/linaro/configs/arndale.conf
+++ b/linaro/configs/arndale.conf
@@ -71,3 +71,4 @@
 CONFIG_DEBUG_INFO=y
 CONFIG_RCU_CPU_STALL_TIMEOUT=60
 CONFIG_DEBUG_USER=y
+CONFIG_TUN=y