dmaengine/ste_dma40: add missing kernel doc for pending_queue

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ste_dma40.c

@@ -174,6 +174,7 @@ struct d40_base;
  * @tasklet: Tasklet that gets scheduled from interrupt context to complete a
  * transfer and call client callback.
  * @client: Cliented owned descriptor list.
+ * @pending_queue: Submitted jobs, to be issued by issue_pending()
  * @active: Active descriptor.
  * @queue: Queued jobs.
  * @dma_cfg: The client configuration of this dma channel.