pinctrl: Add Xilinx ZynqMP pinctrl driver support

Adding pinctrl driver for Xilinx ZynqMP platform.
This driver queries pin information from firmware and registers
pin control accordingly.

Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Link: https://lore.kernel.org/r/1619080202-31924-4-git-send-email-lakshmi.sai.krishna.potthuri@xilinx.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>