ARM: dts: sun7i: Add new i12-tvbox board

The i12 tvbox is an A20 based android tvbox, with 512M / 1G RAM, 4G nand flash,
ap6210 or ap6330 sdio wifi + bt (broadcom sdio wifi + uart attached brcm bt),
2USB host ports using USB-A receptacles and a micro-usb receptacle for USB OTG,
and 100Mbit ethernet using an IP101a phy.

The PCB is labelled i12-a20 hence I've named the board i12-a20. It is used
in noname allwinner A20 tv-boxes, which are sometimes sold with Q5 or
QT840A as product name.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>