reset: berlin: Make reset_control_ops const

The berlin_reset_ops structure is never modified. Make it const.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com>

drivers/reset/reset-berlin.c

@@ -46,7 +46,7 @@ static int berlin_reset_reset(struct reset_controller_dev *rcdev,
 	return 0;
 }
 
-static struct reset_control_ops berlin_reset_ops = {
+static const struct reset_control_ops berlin_reset_ops = {
 	.reset	= berlin_reset_reset,
 };