ARM: socfpga: dts: add support for EBV SOCrates

The SOCrates is a SOCFpga-Cyclone5 based board from EBV.
Add support for it.

Reviewed-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>