ieee802154: cfg802154: make wpan_phy_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the wpan_phy_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Message-ID: <20240305-class_cleanup-wpan-v1-1-376f751fd481@marliere.net>
[changed prefix from wifi to ieee802154 by stefan@datenfreihafen.org]
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
diff --git a/net/ieee802154/sysfs.c b/net/ieee802154/sysfs.c
index d290393..6708160 100644
--- a/net/ieee802154/sysfs.c
+++ b/net/ieee802154/sysfs.c
@@ -93,7 +93,7 @@
 #define WPAN_PHY_PM_OPS NULL
 #endif
 
-struct class wpan_phy_class = {
+const struct class wpan_phy_class = {
 	.name = "ieee802154",
 	.dev_release = wpan_phy_release,
 	.dev_groups = pmib_groups,
diff --git a/net/ieee802154/sysfs.h b/net/ieee802154/sysfs.h
index 337545b..69961e1 100644
--- a/net/ieee802154/sysfs.h
+++ b/net/ieee802154/sysfs.h
@@ -5,6 +5,6 @@
 int wpan_phy_sysfs_init(void);
 void wpan_phy_sysfs_exit(void);
 
-extern struct class wpan_phy_class;
+extern const struct class wpan_phy_class;
 
 #endif /* __IEEE802154_SYSFS_H */