staging: greybus: Constify gb_audio_module_type

Constify static struct kobj_type gb_audio_module_type to prevent
modification of data shared across many instances and to address the
checkpatch warning that "gb_audio_module_type" should be const. The
"gb_audio_module_type" struct is only used in one place:
err = kobject_init_and_add(&m->kobj, &gb_audio_module_type, NULL, ...
so checkpatch is correct that it can be made const.

Signed-off-by: Ayush Tiwari <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Link: https://lore.kernel.org/r/ZfiQsZBrHfImIJfc@ayush-HP-Pavilion-Gaming-Laptop-15-ec0xxx
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/greybus/audio_manager_module.c

···
 };
 ATTRIBUTE_GROUPS(gb_audio_module_default);
 
-static struct kobj_type gb_audio_module_type = {
+static const struct kobj_type gb_audio_module_type = {
 	.sysfs_ops = &gb_audio_module_sysfs_ops,
 	.release = gb_audio_module_release,
 	.default_groups = gb_audio_module_default_groups,