dma: mv_xor: remove hw_id field from platform_data

There is no need for the platform_data to give this ID, it is simply
the channel number, so we can compute it inside the driver when
registering the channels.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index a6a5a28..fc983bf 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -1088,7 +1088,7 @@
 static struct mv_xor_chan *
 mv_xor_channel_add(struct mv_xor_device *xordev,
 		   struct platform_device *pdev,
-		   int hw_id, dma_cap_mask_t cap_mask,
+		   int idx, dma_cap_mask_t cap_mask,
 		   size_t pool_size, int irq)
 {
 	int ret = 0;
@@ -1101,7 +1101,7 @@
 		goto err_free_dma;
 	}
 
-	mv_chan->idx = hw_id;
+	mv_chan->idx = idx;
 
 	dma_dev = &mv_chan->dmadev;
 
@@ -1295,7 +1295,7 @@
 			}
 
 			xordev->channels[i] =
-				mv_xor_channel_add(xordev, pdev, cd->hw_id,
+				mv_xor_channel_add(xordev, pdev, i,
 						   cd->cap_mask,
 						   cd->pool_size, irq);
 			if (IS_ERR(xordev->channels[i])) {