regulator: core: make regulator_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 regulator_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 <[e-mail]>
Suggested-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Ricardo B. Marliere <[e-mail]>
Link: https://msgid.link/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/core.c

···
 };
 #endif
 
-struct class regulator_class = {
+const struct class regulator_class = {
 	.name = "regulator",
 	.dev_release = regulator_dev_release,
 	.dev_groups = regulator_dev_groups,

drivers/regulator/internal.h

···
 	struct dentry *debugfs;
 };
 
-extern struct class regulator_class;
+extern const struct class regulator_class;
 
 static inline struct regulator_dev *dev_to_rdev(struct device *dev)
 {