pinctrl: artpec6: constify pinconf_ops, pinctrl_ops, and pinmux_ops structures

This pinctrl_ops structure is only stored in the const pctlops
field of a pinctrl_desc structure. Make the pinctrl_ops structure
const as well.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Lars Persson <lars.persson@axis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-artpec6.c

@@ -445,7 +445,7 @@ static unsigned int artpec6_pconf_drive_field_to_mA(int field)
 	}
 }
 
-static struct pinctrl_ops artpec6_pctrl_ops = {
+static const struct pinctrl_ops artpec6_pctrl_ops = {
 	.get_group_pins		= artpec6_get_group_pins,
 	.get_groups_count	= artpec6_get_groups_count,
 	.get_group_name		= artpec6_get_group_name,