staging: mt7621-eth: set correct dma mask.

Since commit f8c55dc6 ("MIPS: use generic dma noncoherent ops for
simple noncoherent platforms") changed MIPS dma handling, the eth
driver fails because the dma mask is set on the wrong 'struct device'.

Move the setting to the correct struct device.
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-eth/mtk_eth_soc.c

@@ -1689,6 +1689,8 @@ static int mtk_open(struct net_device *dev)
 	struct mtk_mac *mac = netdev_priv(dev);
 	struct mtk_eth *eth = mac->hw;
 
+	dma_coerce_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
+
 	if (!atomic_read(&eth->dma_refcnt)) {
 		int err = mtk_start_dma(eth);
 
@@ -2062,9 +2064,6 @@ static int mtk_probe(struct platform_device *pdev)
 	struct clk *sysclk;
 	int err;
 
-	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
-	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
-
 	device_reset(&pdev->dev);
 
 	match = of_match_device(of_mtk_match, &pdev->dev);