pinctrl: stm32: fix PM support for stm32mp257

The driver for stm32mp257 is missing the suspend callback in
struct dev_pm_ops.

Add the callback, using the common stm32_pinctrl_suspend()
function.

Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Fixes: 619f8ca ("pinctrl: stm32: add stm32mp257 pinctrl support")
Link: https://lore.kernel.org/r/20240207104604.174843-1-antonio.borneo@foss.st.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: AntonioBorneo

drivers/pinctrl/stm32/pinctrl-stm32mp257.c

@@ -2562,7 +2562,7 @@ static const struct of_device_id stm32mp257_pctrl_match[] = {
 };
 
 static const struct dev_pm_ops stm32_pinctrl_dev_pm_ops = {
-	 SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, stm32_pinctrl_resume)
+	 SET_LATE_SYSTEM_SLEEP_PM_OPS(stm32_pinctrl_suspend, stm32_pinctrl_resume)
 };
 
 static struct platform_driver stm32mp257_pinctrl_driver = {