pinctrl: at91: convert to NOIRQ_SYSTEM_SLEEP_PM_OPS

With the old SET_NOIRQ_SYSTEM_SLEEP_PM_OPS, some configs result in a
build warning:

drivers/pinctrl/pinctrl-at91.c:1668:12: error: 'at91_gpio_resume' defined but not used [-Werror=unused-function]
 1668 | static int at91_gpio_resume(struct device *dev)
      |            ^~~~~~~~~~~~~~~~
drivers/pinctrl/pinctrl-at91.c:1650:12: error: 'at91_gpio_suspend' defined but not used [-Werror=unused-function]
 1650 | static int at91_gpio_suspend(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Link: https://lore.kernel.org/r/20221215164301.934805-1-arnd@kernel.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>