pinctrl: da9062: add driver support

The DA9062 is a mfd pmic device which supports 5 GPIOs. The GPIOs can
be used as input, output or have a special use-case.

The patch adds the support for the normal input/output use-case.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20200108104746.1765-4-m.felsch@pengutronix.de
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>