serial: 21285: constify uart_ops structures

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/21285.c

@@ -334,7 +334,7 @@ static int serial21285_verify_port(struct uart_port *port, struct serial_struct
 	return ret;
 }
 
-static struct uart_ops serial21285_ops = {
+static const struct uart_ops serial21285_ops = {
 	.tx_empty	= serial21285_tx_empty,
 	.get_mctrl	= serial21285_get_mctrl,
 	.set_mctrl	= serial21285_set_mctrl,