drm/ttm: fix ttm_kmap_iter.h kernel-doc warnings

There's no proper way to document function pointer members, but at least
silence the warnings.

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e80e74ac4b6c5f1df3bc2dd98651ba289aae8e83.1709898638.git.jani.nikula@intel.com

include/drm/ttm/ttm_kmap_iter.h

@@ -20,7 +20,7 @@ struct iosys_map;
  */
 struct ttm_kmap_iter_ops {
 	/**
-	 * kmap_local() - Map a PAGE_SIZE part of the resource using
+	 * @map_local: Map a PAGE_SIZE part of the resource using
 	 * kmap_local semantics.
 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
 	 * the resource.
@@ -31,7 +31,7 @@ struct ttm_kmap_iter_ops {
 	void (*map_local)(struct ttm_kmap_iter *res_iter,
 			  struct iosys_map *dmap, pgoff_t i);
 	/**
-	 * unmap_local() - Unmap a PAGE_SIZE part of the resource previously
+	 * @unmap_local: Unmap a PAGE_SIZE part of the resource previously
 	 * mapped using kmap_local.
 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
 	 * the resource.