sunxi: add support for NetCube Systems Kumquat

sunxi: add support for NetCube Systems Kumquat

NetCube Systems Kumquat is a board based on the Allwinner V3s SoC,
including:

- 64MB DDR2 included in SoC
- 10/100 Mbps Ethernet
- USB-C DRD
- Audio Codec
- Isolated CAN-FD
- ESP32 over SDIO
- 8MB SPI-NOR Flash for bootloader
- I2C EEPROM for MAC addresses
- SDIO Connector for eMMC or SD-Card
- 8x 12/24V IOs, 4x normally open relays
- DS3232 RTC with Battery Backup
- QWIIC connectors for external I2C devices

Signed-off-by: Lukas Schmid <lukas.schmid@netcube.li>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>