ARM: dts: sun4i: Add Marsboard A10 board

This patch add support for Marsboard A10 board.

The Marsboard A10 is a A10 based development board with 1G RAM, 1G NAND,
micro SD card slot, SATA 2.0 socket, 10/100 ethernet, mini HDMI port,
1 USB OTG port and 2 USB 2.0 ports. Board does not use the AXP209 pmic,
it does not have a pmic at all.
Board also have 2 expansion 70 pin headers.

Signed-off-by: Aleksei Mamlin <mamlinav@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>