ARM: sun4i: dt: Add new LinkSprite pcDuino2 board

The LinkSprite pcDuino2 board is almost identical to the older
LinkSprite pcDuino1 board according to the schematic pdf files.
So we just include the existing "sun4i-a10-pcduino.dts" file and
make the necessary adjustments.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>