pinctrl: exynos: Add irq_chip instance for Exynos7 wakeup interrupts

Exynos7 uses different offsets for wakeup interrupt configuration registers.
So a new irq_chip instance for Exynos7 wakeup interrupts is added. The irq_chip
selection is now based on the wakeup interrupt controller compatible string.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Reviewed-by: Thomas Abraham <thomas.ab@samsung.com>
Tested-by: Thomas Abraham <thomas.ab@samsung.com>
Acked-by: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>