gpio: crystalcove: set IRQCHIP_SKIP_SET_WAKE for the irqchip

The CrystalCove GPIO irqchip doesn't have irq_set_wake callback defined
so we should set IRQCHIP_SKIP_SET_WAKE for it or it would cause an irq
desc's wake_depth unbalanced warning during system resume phase from the
gpio_keys driver, which is the driver for the power button of the ASUS
T100 laptop.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>