dt-bindings: pinctrl: sunxi: Add compatible string for A83T R_PIO

The R_PIO on the A83T is almost the same as the one found on the A64,
except that the CIR_RX function was moved from pin PL11 to pin PL12.

Add a compatible string for it.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>