rcar-hpbdma: fixup channel busy check for double plane

The device busy check method is different between
single and double planes.
It will always return "busy" without this patch
if channel used as double plane.
Reviewed-by: Max Filippov <max.filippov@cogentembedded.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sh/rcar-hpbdma.c

@@ -60,6 +60,7 @@
 #define HPB_DMAE_DSTPR_DMSTP	BIT(0)
 
 /* DMA status register (DSTSR) bits */
+#define HPB_DMAE_DSTSR_DQSTS	BIT(2)
 #define HPB_DMAE_DSTSR_DMSTS	BIT(0)
 
 /* DMA common registers */
@@ -385,7 +386,10 @@ static bool hpb_dmae_channel_busy(struct shdma_chan *schan)
 	struct hpb_dmae_chan *chan = to_chan(schan);
 	u32 dstsr = ch_reg_read(chan, HPB_DMAE_DSTSR);
 
-	return (dstsr & HPB_DMAE_DSTSR_DMSTS) == HPB_DMAE_DSTSR_DMSTS;
+	if (chan->xfer_mode == XFER_DOUBLE)
+		return dstsr & HPB_DMAE_DSTSR_DQSTS;
+	else
+		return dstsr & HPB_DMAE_DSTSR_DMSTS;
 }
 
 static int