mtd: onenand: omap2: Pass correct flags for prep_dma_memcpy

The commit converting the driver to DMAengine was missing the flags for
the memcpy prepare call.
It went unnoticed since the omap-dma driver was ignoring them.

Fixes: 3ed6a4d1 (" mtd: onenand: omap2: Convert to use dmaengine for memcp")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/onenand/omap2.c

@@ -328,7 +328,8 @@ static inline int omap2_onenand_dma_transfer(struct omap2_onenand *c,
 	struct dma_async_tx_descriptor *tx;
 	dma_cookie_t cookie;
 
-	tx = dmaengine_prep_dma_memcpy(c->dma_chan, dst, src, count, 0);
+	tx = dmaengine_prep_dma_memcpy(c->dma_chan, dst, src, count,
+				       DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
 	if (!tx) {
 		dev_err(&c->pdev->dev, "Failed to prepare DMA memcpy\n");
 		return -EIO;