pinctrl: sunxi: add support for the Allwinner A100 pin controller

This commit introduces support for the pin controller on A100.

Signed-off-by: Yangtao Li <frank@allwinnertech.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/4e331a2ed4a30c883df6157bc5c52bb686aa8e0d.1595572867.git.frank@allwinnertech.com


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