mailbox: bcm-pdc: Fix some kernel-doc comments

Fix some kernel-doc comments to silence the warnings:

drivers/mailbox/bcm-pdc-mailbox.c:707: warning: Function parameter or member 'pdcs' not described in 'pdc_tx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:707: warning: Excess function parameter 'spu_idx' description in 'pdc_tx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:875: warning: Function parameter or member 'pdcs' not described in 'pdc_rx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:875: warning: Excess function parameter 'spu_idx' description in 'pdc_rx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:966: warning: Function parameter or member 't' not described in 'pdc_tasklet_cb'
drivers/mailbox/bcm-pdc-mailbox.c:966: warning: Excess function parameter 'data' description in 'pdc_tasklet_cb'
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/bcm-pdc-mailbox.c

@@ -694,7 +694,7 @@ pdc_receive(struct pdc_state *pdcs)
  * pdc_tx_list_sg_add() - Add the buffers in a scatterlist to the transmit
  * descriptors for a given SPU. The scatterlist buffers contain the data for a
  * SPU request message.
- * @spu_idx:   The index of the SPU to submit the request to, [0, max_spu)
+ * @pdcs:      PDC state for the SPU that will process this request
  * @sg:        Scatterlist whose buffers contain part of the SPU request
  *
  * If a scatterlist buffer is larger than PDC_DMA_BUF_MAX, multiple descriptors
@@ -861,7 +861,7 @@ static int pdc_rx_list_init(struct pdc_state *pdcs, struct scatterlist *dst_sg,
  * pdc_rx_list_sg_add() - Add the buffers in a scatterlist to the receive
  * descriptors for a given SPU. The caller must have already DMA mapped the
  * scatterlist.
- * @spu_idx:    Indicates which SPU the buffers are for
+ * @pdcs:       PDC state for the SPU that will process this request
  * @sg:         Scatterlist whose buffers are added to the receive ring
  *
  * If a receive buffer in the scatterlist is larger than PDC_DMA_BUF_MAX,
@@ -960,7 +960,7 @@ static irqreturn_t pdc_irq_handler(int irq, void *data)
 /**
  * pdc_tasklet_cb() - Tasklet callback that runs the deferred processing after
  * a DMA receive interrupt. Reenables the receive interrupt.
- * @data: PDC state structure
+ * @t: Pointer to the Altera sSGDMA channel structure
  */
 static void pdc_tasklet_cb(struct tasklet_struct *t)
 {