pinctrl: mvebu: pinctrl driver for 98DX3236 SoC

This pinctrl driver supports the 98DX3236, 98DX3336 and 98DX4251 SoCs
from Marvell.

Signed-off-by: Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>