sunxi: Add defconfig for yones toptech bs1078-v2 tablet

sunxi: Add defconfig for yones toptech bs1078-v2 tablet

The yones toptech bs1078-v2 is a 10.1" tablet without any clear markings on
the outside, but 'YONESTOPTECH-BS1078' written on the PCB silkscreen.

It features a 16:9 1024:600 LCD, A31s SoC, 1GB RAM, 8G NAND, silead gsl3675
touchscreen and a RTL8723AS wifi chip:

https://linux-sunxi.org/Yones_Toptech_BS1078_V2

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>