nfc: pn533: Constify serdev_device_ops

The only usage of pn532_serdev_ops is to pass its address to
serdev_device_set_client_ops(), which takes a pointer to const
serdev_device_ops as argument. Make it const to allow the compiler to
put it in read-only memory.
Signed-off-by: NRikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/nfc/pn533/uart.c

@@ -224,7 +224,7 @@ static int pn532_receive_buf(struct serdev_device *serdev,
 	return i;
 }
 
-static struct serdev_device_ops pn532_serdev_ops = {
+static const struct serdev_device_ops pn532_serdev_ops = {
 	.receive_buf = pn532_receive_buf,
 	.write_wakeup = serdev_device_write_wakeup,
 };