arm64: marvell: enable the Armada 7K/8K pinctrl driver

This commit makes sure the drivers for the Armada 7K/8K pin controllers
are enabled.

Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>