wifi: mac80211_hwsim: change hwsim_class to a const struct

wifi: mac80211_hwsim: change hwsim_class to a const struct

The class_create() call has been deprecated in favor of class_register()
as the driver core now allows for a struct class to be in read-only
memory. Change hwsim_class to be a const struct class and drop the
class_create() call.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
Link: https://patch.msgid.link/20260303165938.3773998-1-jkoolstra@xs4all.nl
Signed-off-by: Johannes Berg <johannes.berg@intel.com>