Documentation: dt: socfpga: Add Arria10 SD-MMC EDAC binding

Add the device tree bindings needed to support the Altera SD-MMC
FIFO buffers EDAC on the Arria10 chip.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: dinguyen@opensource.altera.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1470153381-20517-2-git-send-email-tthayer@opensource.altera.com


Signed-off-by: Borislav Petkov <bp@suse.de>