dmaengine: qcom: bam_dma: fix some doc warnings.

Building kernel with W=1 throws up below warnings:
bam_dma.c:459: warning: Function parameter or member 'dir'
	not described in 'bam_chan_init_hw'
bam_dma.c:697: warning: Function parameter or member 'chan'
	not described in 'bam_dma_terminate_all'
bam_dma.c:697: warning: Excess function parameter 'bchan'
	description in 'bam_dma_terminate_all'
bam_dma.c:964: warning: Function parameter or member 'bchan'
	not described in 'bam_start_dma'

Fix these!.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/qcom/bam_dma.c

@@ -451,6 +451,7 @@ static void bam_reset_channel(struct bam_chan *bchan)
 /**
  * bam_chan_init_hw - Initialize channel hardware
  * @bchan: bam channel
+ * @dir: DMA transfer direction
  *
  * This function resets and initializes the BAM channel
  */
@@ -679,7 +680,7 @@ err_out:
 
 /**
  * bam_dma_terminate_all - terminate all transactions on a channel
- * @bchan: bam dma channel
+ * @chan: bam dma channel
  *
  * Dequeues and frees all transactions
  * No callbacks are done
@@ -951,7 +952,7 @@ static void bam_apply_new_config(struct bam_chan *bchan,
 
 /**
  * bam_start_dma - start next transaction
- * @bchan - bam dma channel
+ * @bchan: bam dma channel
  */
 static void bam_start_dma(struct bam_chan *bchan)
 {