sun7i: Add support for the Wits Pro A20 DKT board

sun7i: Add support for the Wits Pro A20 DKT board

The Wits Pro A20 DKT is an A20 Development KiT with 1G RAM, 4G NAND, sdio wifi,
1Gbit ethernet, 1024x768 lcd screen with ft5x_ts touchscreen and a ton of
IO connectors.

Note there seem to be multiple sdcard slots on the board (4 in total), but
other then mmc0 none of these are hooked up by default, there is a ton of
dip-switches which likely allow hooking some of these up, but the documentation
of the board only describes the use of a fraction of them, so for now we
only support mmc0.

Also see: http://www.merrii.com/en/pla_d.asp?id=163

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>