pinctrl: mvebu: pinctrl driver for 98DX2530 SoC

This pinctrl driver supports the 98DX25xx and 98DX35xx family of chips
from Marvell. It is based on the Marvell SDK with additions for various
(non-gpio) pin configurations based on the datasheet.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220414233055.586962-3-chris.packham@alliedtelesis.co.nz
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>