net: dsa: include dsa.h only once

The public include/net/dsa.h file is meant for DSA drivers, while all
DSA core files share a common private header net/dsa/dsa_priv.h file.

Ensure that dsa_priv.h is the only DSA core file to include net/dsa.h,
and add a new line to separate absolute and relative headers at the same
time.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 2ac6234..4301f52 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -18,7 +18,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/of.h>
 #include <linux/of_net.h>
-#include <net/dsa.h>
+
 #include "dsa_priv.h"
 
 static LIST_HEAD(dsa_switch_trees);