pinctrl: Declare operation structures as const

The pinconf, pinctrl and pinmux operation structures hold function
pointers that are never modified. Declare them as const.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinctrl-sunxi.c b/drivers/pinctrl/pinctrl-sunxi.c
index 80b11e3..46b8f2d 100644
--- a/drivers/pinctrl/pinctrl-sunxi.c
+++ b/drivers/pinctrl/pinctrl-sunxi.c
@@ -1029,7 +1029,7 @@
 	kfree(map);
 }
 
-static struct pinctrl_ops sunxi_pctrl_ops = {
+static const struct pinctrl_ops sunxi_pctrl_ops = {
 	.dt_node_to_map		= sunxi_pctrl_dt_node_to_map,
 	.dt_free_map		= sunxi_pctrl_dt_free_map,
 	.get_groups_count	= sunxi_pctrl_get_groups_count,
@@ -1098,7 +1098,7 @@
 	return 0;
 }
 
-static struct pinconf_ops sunxi_pconf_ops = {
+static const struct pinconf_ops sunxi_pconf_ops = {
 	.pin_config_group_get	= sunxi_pconf_group_get,
 	.pin_config_group_set	= sunxi_pconf_group_set,
 };
@@ -1204,7 +1204,7 @@
 	return ret;
 }
 
-static struct pinmux_ops sunxi_pmx_ops = {
+static const struct pinmux_ops sunxi_pmx_ops = {
 	.get_functions_count	= sunxi_pmx_get_funcs_cnt,
 	.get_function_name	= sunxi_pmx_get_func_name,
 	.get_function_groups	= sunxi_pmx_get_func_groups,