tifm: make tifm_adapter_class constant

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 tifm_adapter_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>
Link: https://lore.kernel.org/r/20240301-class_cleanup-char-misc-v1-1-4e2a41bef8cc@marliere.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/tifm_core.c

@@ -166,7 +166,7 @@ static void tifm_free(struct device *dev)
 	kfree(fm);
 }
 
-static struct class tifm_adapter_class = {
+static const struct class tifm_adapter_class = {
 	.name    = "tifm_adapter",
 	.dev_release = tifm_free
 };