gpio: pca953x: Configure wake-up path when wake-up is enabled

If a device is part of the wake-up path, it should indicate this by
setting its power.wakeup_path field.  This allows the genpd core code to
keep the device enabled during system suspend when needed.

As regulators powering devices are not handled by genpd, the driver
handles these itself, and thus must skip regulator control when the
device is part of the wake-up path.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>