usb: typec: constify struct class usage

Since commit 43a7206b ("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 structures typec_mux_class, retimer_class and
typec_class to be declared at build time placing them 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>
Link: https://lore.kernel.org/r/20240301-class_cleanup-usb-v1-1-50309e325095@marliere.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/class.c

@@ -21,7 +21,7 @@
 
 static DEFINE_IDA(typec_index_ida);
 
-struct class typec_class = {
+const struct class typec_class = {
 	.name = "typec",
 };
 

drivers/usb/typec/class.h

@@ -93,9 +93,9 @@ extern const struct device_type typec_port_dev_type;
 #define is_typec_plug(dev) ((dev)->type == &typec_plug_dev_type)
 #define is_typec_port(dev) ((dev)->type == &typec_port_dev_type)
 
-extern struct class typec_mux_class;
-extern struct class retimer_class;
-extern struct class typec_class;
+extern const struct class typec_mux_class;
+extern const struct class retimer_class;
+extern const struct class typec_class;
 
 #if defined(CONFIG_ACPI)
 int typec_link_ports(struct typec_port *connector);

drivers/usb/typec/mux.c

@@ -469,6 +469,6 @@ void *typec_mux_get_drvdata(struct typec_mux_dev *mux_dev)
 }
 EXPORT_SYMBOL_GPL(typec_mux_get_drvdata);
 
-struct class typec_mux_class = {
+const struct class typec_mux_class = {
 	.name = "typec_mux",
 };

drivers/usb/typec/retimer.c

@@ -155,6 +155,6 @@ void *typec_retimer_get_drvdata(struct typec_retimer *retimer)
 }
 EXPORT_SYMBOL_GPL(typec_retimer_get_drvdata);
 
-struct class retimer_class = {
+const struct class retimer_class = {
 	.name = "retimer",
 };