dts: socfpga: Add support for Altera's SOCFPGA Arria V board

Add support for a new SOCFPGA board that has an Arria V FPGA along with
dual ARM Cortex-A9 cores.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Cc: Pavel Machek <pavel@denx.de>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: devicetree@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org