pinctrl: imx: add driver for i.MX8MQ

The i.MX8MQ pincontrol works in a similar way to the earlier i.MX SoCs.
This driver builds on top of the imx specific pinconf handling.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>