ARM: dts: imx6dl-yapp4: Add Y Soft IOTA Orion board

Add devicetree for new variant of the Y Soft IOT appliance.
The board is based on Hydra with the following changes:

 - faster SoC (1GHz), 4GB RAM and 64GB eMMC
 - removed miniPCIe
 - removed Audio jack
 - removed uSD slot
 - removed RJ10 serial
 - HDMI replaced by USB host

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>