net: dsa: move headers exported by switch.c to switch.h

Reduce code bloat in dsa_priv.h by moving the prototypes exported by
switch.h into their own header file.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/dsa2.c

@@ -22,6 +22,7 @@
 #include "master.h"
 #include "port.h"
 #include "slave.h"
+#include "switch.h"
 #include "tag.h"
 
 static DEFINE_MUTEX(dsa2_mutex);

net/dsa/dsa_priv.h

@@ -155,10 +155,6 @@ bool dsa_schedule_work(struct work_struct *work);
 /* netlink.c */
 extern struct rtnl_link_ops dsa_link_ops __read_mostly;
 
-/* switch.c */
-int dsa_switch_register_notifier(struct dsa_switch *ds);
-void dsa_switch_unregister_notifier(struct dsa_switch *ds);
-
 static inline bool dsa_switch_supports_uc_filtering(struct dsa_switch *ds)
 {
 	return ds->ops->port_fdb_add && ds->ops->port_fdb_del &&

net/dsa/port.c

@@ -15,6 +15,7 @@
 #include "dsa_priv.h"
 #include "port.h"
 #include "slave.h"
+#include "switch.h"
 
 /**
  * dsa_port_notify - Notify the switching fabric of changes to a port

net/dsa/switch.c

@@ -15,6 +15,7 @@
 #include "dsa_priv.h"
 #include "port.h"
 #include "slave.h"
+#include "switch.h"
 
 static unsigned int dsa_switch_fastest_ageing_time(struct dsa_switch *ds,
 						   unsigned int ageing_time)

net/dsa/switch.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_SWITCH_H
+#define __DSA_SWITCH_H
+
+struct dsa_switch;
+
+int dsa_switch_register_notifier(struct dsa_switch *ds);
+void dsa_switch_unregister_notifier(struct dsa_switch *ds);
+
+#endif

net/dsa/tag_8021q.c

@@ -9,6 +9,7 @@
 
 #include "dsa_priv.h"
 #include "port.h"
+#include "switch.h"
 #include "tag.h"
 
 /* Binary structure of the fake 12-bit VID field (when the TPID is