mtd: rawnand: omap2: Pass the parent of pdev to dma_request_chan()

Commit e1e6255c ("mtd: rawnand: omap2: convert driver to
nand_scan()") moved part of the init code in the ->attach_chip hook
and at the same time changed the struct device object passed to
dma_request_chan() (&pdev->dev instead of pdev->dev.parent).

Fixes: e1e6255c ("mtd: rawnand: omap2: convert driver to nand_scan()")
Reported-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/raw/omap2.c

@@ -1944,7 +1944,7 @@ static int omap_nand_attach_chip(struct nand_chip *chip)
 	case NAND_OMAP_PREFETCH_DMA:
 		dma_cap_zero(mask);
 		dma_cap_set(DMA_SLAVE, mask);
-		info->dma = dma_request_chan(dev, "rxtx");
+		info->dma = dma_request_chan(dev->parent, "rxtx");
 
 		if (IS_ERR(info->dma)) {
 			dev_err(dev, "DMA engine request failed\n");