drm/suballoc: fix drm_suballoc.h kernel-doc

Rename dma_fence to fence to match code.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/36d18b315fd9a6788484667f644b3fea347fb007.1709749576.git.jani.nikula@intel.com

include/drm/drm_suballoc.h

@@ -37,7 +37,7 @@ struct drm_suballoc_manager {
  * @manager: The drm_suballoc_manager.
  * @soffset: Start offset.
  * @eoffset: End offset + 1 so that @eoffset - @soffset = size.
- * @dma_fence: The fence protecting the allocation.
+ * @fence: The fence protecting the allocation.
  */
 struct drm_suballoc {
 	struct list_head olist;