pinctrl: sunxi: Add driver for Allwinner D1

This SoC contains a pinctrl with a new register layout. Use the variant
parameter to set the right register offsets. This pinctrl also increases
the number of functions per pin from 8 to 16, taking advantage of all 4
bits in the mux config field (so far, only functions 0-8 and 14-15 are
used). This increases the maximum possible number of functions.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20220713025233.27248-7-samuel@sholland.org


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