ARM: dts: sun8i: Add ET-Q8 A33 support

ET-Q8_A33 is A33 based cheap tablet in common Q8 format.

It has 512MB RAM, 4GB Nand, 7" Display, RDA5900P wifi, GSL1680 touch, etc.

Signed-off-by: Vishnu Patekar <vishnupatekar0510@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Chen-Yu Tsai <wens@csie.org>