reset: img: Make reset_control_ops const

The pistachio_reset_ops structure is never modified. Make it const.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: James Hartley <james.hartley@imgtec.com>

drivers/reset/reset-pistachio.c

@@ -97,7 +97,7 @@ static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
 				  mask, 0);
 }
 
-static struct reset_control_ops pistachio_reset_ops = {
+static const struct reset_control_ops pistachio_reset_ops = {
 	.assert		= pistachio_reset_assert,
 	.deassert	= pistachio_reset_deassert,
 };