sunxi: Add new Mele_A1000G_quad defconfig

The Mele A1000G-quad and the Mele M9 have the same PCB, sofar we've been
using the same defconfig (and dts on the kernel side) for both models.
Unfortunately this does not work for the otg controller, on the M9 this
is routed to a micro-usb connector on the outside, while as on the
A1000G-quad it is connected to an usb to sata bridge.

This commit adds a new defconfig for the Mele-A1000G-quad to allow using
different otg controller settings on the 2 boards.

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