drm/i915/huc: use const struct bus_type pointers

The struct bus_type pointers in the functions
intel_huc_register_gsc_notifier() and
intel_huc_unregister_gsc_notifier() should be a const pointer, as the
structure is not modified anywhere in the functions, and the pointer
they are passed will be a const * in the near future.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tony Ye <tony.ye@intel.com>
Cc: Vitaly Lubart <vitaly.lubart@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-30-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/i915/gt/uc/intel_huc.c

@@ -183,7 +183,7 @@ static int gsc_notifier(struct notifier_block *nb, unsigned long action, void *d
 	return 0;
 }
 
-void intel_huc_register_gsc_notifier(struct intel_huc *huc, struct bus_type *bus)
+void intel_huc_register_gsc_notifier(struct intel_huc *huc, const struct bus_type *bus)
 {
 	int ret;
 
@@ -200,7 +200,7 @@ void intel_huc_register_gsc_notifier(struct intel_huc *huc, struct bus_type *bus
 	}
 }
 
-void intel_huc_unregister_gsc_notifier(struct intel_huc *huc, struct bus_type *bus)
+void intel_huc_unregister_gsc_notifier(struct intel_huc *huc, const struct bus_type *bus)
 {
 	if (!huc->delayed_load.nb.notifier_call)
 		return;

drivers/gpu/drm/i915/gt/uc/intel_huc.h

@@ -51,8 +51,8 @@ int intel_huc_check_status(struct intel_huc *huc);
 void intel_huc_update_auth_status(struct intel_huc *huc);
 bool intel_huc_is_authenticated(struct intel_huc *huc);
 
-void intel_huc_register_gsc_notifier(struct intel_huc *huc, struct bus_type *bus);
-void intel_huc_unregister_gsc_notifier(struct intel_huc *huc, struct bus_type *bus);
+void intel_huc_register_gsc_notifier(struct intel_huc *huc, const struct bus_type *bus);
+void intel_huc_unregister_gsc_notifier(struct intel_huc *huc, const struct bus_type *bus);
 
 static inline int intel_huc_sanitize(struct intel_huc *huc)
 {