ARM: sun5i: chip: add a node for the w1 gpio controller

The CHIP uses a 1-Wire bus to discover the DIPs. Enable the bus in the DT.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>