sunxi: add support for FriendlyARM Nano PI NEO Air dev board

sunxi: add support for FriendlyARM Nano PI NEO Air dev board

Hardware:

  Allwinner H3 upto 1.2GHz
  512MB DDR3 RAM
  8GB on-board eMMC - mountable, can be used as boot with custom boot.scr
  microSD-card slot
  WiFi 802.11n (AP6212A) - working
  Bluetooth (AP6212A) - not working for now
  Micro-USB OTG + 2*USB headers
  UART 3.3V - working
  GPIO/I2C/SPI 2.54mm headers

Standard sunxi SD-card installation procedure - copy image to SD card,
insert in into slot and boot. First time you will need UART adapter to
enable on-board wireless (or just build custom image with enabled WiFi).

To boot from eMMC:

  - boot from SD
  - copy SD image to emmc (dd bs=... if=.... of=/dev/mmcblk2)
  - mount eMMC boot partition and replace boot script on it
  - unmount, reboot

To use i2c, spi and more uarts - replace dtb on boot partition with
fixed one (use dtc or fdt-tools).

Signed-off-by: Roman Bazalevsky <rvb@rvb.name>
[rebase onto device name consolidation patches]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>