drm/exynos: ipp: remove description of non-existing field

ipp_id field is removed from exynos_drm_ippdrv struct.
The patch removes its description as well.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_ipp.h

@@ -142,7 +142,6 @@ struct exynos_drm_ipp_ops {
  * @parent_dev: parent device information.
  * @dev: platform device.
  * @drm_dev: drm device.
- * @ipp_id: id of ipp driver.
  * @dedicated: dedicated ipp device.
  * @ops: source, destination operations.
  * @event_workq: event work queue.