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-nomadik.c b/drivers/pinctrl/pinctrl-nomadik.c
index 36d2029..2328baa 100644
--- a/drivers/pinctrl/pinctrl-nomadik.c
+++ b/drivers/pinctrl/pinctrl-nomadik.c
@@ -1764,7 +1764,7 @@
 	return 0;
 }
 
-static struct pinctrl_ops nmk_pinctrl_ops = {
+static const struct pinctrl_ops nmk_pinctrl_ops = {
 	.get_groups_count = nmk_get_groups_cnt,
 	.get_group_name = nmk_get_group_name,
 	.get_group_pins = nmk_get_group_pins,
@@ -1975,7 +1975,7 @@
 	/* Set the pin to some default state, GPIO is usually default */
 }
 
-static struct pinmux_ops nmk_pinmux_ops = {
+static const struct pinmux_ops nmk_pinmux_ops = {
 	.get_functions_count = nmk_pmx_get_funcs_cnt,
 	.get_function_name = nmk_pmx_get_func_name,
 	.get_function_groups = nmk_pmx_get_func_groups,
@@ -2089,7 +2089,7 @@
 	return 0;
 }
 
-static struct pinconf_ops nmk_pinconf_ops = {
+static const struct pinconf_ops nmk_pinconf_ops = {
 	.pin_config_get = nmk_pin_config_get,
 	.pin_config_set = nmk_pin_config_set,
 };