sunxi: Add support for the UTOO P66 tablet

The UTOO P66 is a 6" A13 tablet / lcd ereader. It features a 6" 480x800 ips
lcd screen, 512MB RAM & 4GB emmc.

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