pinctrl: nuvoton: Constify wpcm450_groups

There is no modifications are assumed for wpcm450_groups. Constify it.

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/nuvoton/pinctrl-wpcm450.c

···
 #undef WPCM450_GRP
 };
 
-static struct pingroup wpcm450_groups[] = {
+static const struct pingroup wpcm450_groups[] = {
 #define WPCM450_GRP(x) PINCTRL_PINGROUP(#x, x ## _pins, ARRAY_SIZE(x ## _pins))
 	WPCM450_GRPS
 #undef WPCM450_GRP