pinctrl: st: add IRQCHIP_SKIP_SET_WAKE flag

no .irq_set_wake API is available for pinctrl-st driver.
Add the IRQCHIP_SKIP_SET_WAKE flag to inform irq handler
not to call this API.

Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>