pinctrl: sunxi: Add A80 pinctrl muxing options

The A80 has a rather usual pin controller, the only thing out of the ordinary
being that it has 5 interrupts banks, and that some pins have several options
for the same functions.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>