sunxi: add support for FriendlyArm Zeropi

sunxi: add support for FriendlyArm Zeropi

Specification

    CPU: Allwinner H3, Quad-core Cortex-A7 Up to 1.2GHz
    DDR3 RAM: 256MB/512MB
    Connectivity: 10/100/1000Mbps Ethernet
    USB Host: Type-A x 1
    MicroSD Slot x 1
    MicroUSB: for power input only
    Debug Serial Port: 4Pin, 2.54 mm pitch pin header
    Power Supply: DC 5V/2A
    PCB Dimension: 40 x 40 x 1.2mm

Installation:

    Burn the image file to an SD Card with dd or any image burning tool
    Boot ZeroPi from the SD Card

The following features are working and tested:

    Ethernet port 10/100/1000M Ethernet

Remarks: SBC is mostly compatible and boots with FriendlyARM NanoPI M1 plus DTS also (zeropi has no working hdmi)

Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com>