drm/ast: Use drm_atomic_helper_commit_tail() helper

Ast has no special requirements for runtime power management. So
replace drm_atomic_helper_commit_tail_rpm() with the regular helper
drm_atomic_helper_commit_tail().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240627153638.8765-9-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_mode.c

@@ -1865,7 +1865,7 @@ static void ast_mode_config_helper_atomic_commit_tail(struct drm_atomic_state *s
 	 * the I/O-register lock. Released in atomic_flush().
 	 */
 	mutex_lock(&ast->modeset_lock);
-	drm_atomic_helper_commit_tail_rpm(state);
+	drm_atomic_helper_commit_tail(state);
 	mutex_unlock(&ast->modeset_lock);
 }