Fix pl08x warnings

drivers/dma/amba-pl08x.c: In function 'pl08x_desc_free':
drivers/dma/amba-pl08x.c:1173:2: warning: passing argument 1 of 'dma_descriptor_unmap' from incompatible pointer type
include/linux/dmaengine.h:476:91: note: expected 'struct dma_async_tx_descriptor *' but argument is of type 'struct pl08x_txd *'

Fixes: d38a8c6 ("dmaengine: prepare for generic 'unmap' data")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/amba-pl08x.c

@@ -1169,7 +1169,7 @@ static void pl08x_desc_free(struct virt_dma_desc *vd)
 	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
 	struct pl08x_dma_chan *plchan = to_pl08x_chan(vd->tx.chan);
 
-	dma_descriptor_unmap(txd);
+	dma_descriptor_unmap(&vd->tx);
 	if (!txd->done)
 		pl08x_release_mux(plchan);