pinctrl: stm32: Optimizes and enhances stm32gpio irqchip

- removes unneeded irq_chip.irq_eoi callback
- adds irq_chip.irq_set_wake callback for possible
  in the future GPIO wakeup
- adds irq_chip.irq_ack callback

Signed-off-by: Radoslaw Pietrzyk <radoslaw.pietrzyk@gmail.com>
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
Tested-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>