sunxi: Add defconfig for icnova-a20-swac

sunxi: Add defconfig for icnova-a20-swac

The ICnova-A20-SWAC is a baseboard, equipped with the ICnova-A20 SoM from
In-Circuit:

http://wiki.in-circuit.de/index.php5?title=ICnova_A20_SODIMM
http://linux-sunxi.org/In-Circuit_ICnova_A20

This patch adds support for this board, including ethernet, LCD and USB
support.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>