mpsc: use dma_set_mask insted of dma_supported

This ensures the dma mask that is supported by the driver is recorded
in the device structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/mpsc.c

@@ -753,7 +753,7 @@ static int mpsc_alloc_ring_mem(struct mpsc_port_info *pi)
 		pi->port.line);
 
 	if (!pi->dma_region) {
-		if (!dma_supported(pi->port.dev, 0xffffffff)) {
+		if (!dma_set_mask(pi->port.dev, 0xffffffff)) {
 			printk(KERN_ERR "MPSC: Inadequate DMA support\n");
 			rc = -ENXIO;
 		} else if ((pi->dma_region = dma_alloc_noncoherent(pi->port.dev,