ARM: dts: Add devicetree for OrangePi i96 board

Add initial devicetree for Orange Pi i96 board from Xunlong. It
is one of the 96Boards IoT Edition board.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>