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 <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: linux-edac <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Borislav Petkov <[e-mail]>

Documentation/devicetree/bindings/arm/altera/socfpga-eccmgr.txt

···
 - interrupts      : Should be single bit error interrupt, then double bit error
 	interrupt, in this order.
 
+SDMMC FIFO ECC
+Required Properties:
+- compatible      : Should be "altr,socfpga-sdmmc-ecc"
+- reg             : Address and size for ECC block registers.
+- altr,ecc-parent : phandle to parent SD/MMC node.
+- interrupts      : Should be single bit error interrupt, then double bit error
+	interrupt, in this order for port A, and then single bit error interrupt,
+	then double bit error interrupt in this order for port B.
+
 Example:
 
 	eccmgr: eccmgr@ffd06000 {
···
 			altr,ecc-parent = <&qspi>;
 			interrupts = <14 IRQ_TYPE_LEVEL_HIGH>,
 				     <46 IRQ_TYPE_LEVEL_HIGH>;
+		};
+
+		sdmmc-ecc@ff8c2c00 {
+			compatible = "altr,socfpga-sdmmc-ecc";
+			reg = <0xff8c2c00 0x400>;
+			altr,ecc-parent = <&mmc>;
+			interrupts = <15 IRQ_TYPE_LEVEL_HIGH>,
+				     <47 IRQ_TYPE_LEVEL_HIGH>,
+				     <16 IRQ_TYPE_LEVEL_HIGH>,
+				     <48 IRQ_TYPE_LEVEL_HIGH>;
 		};
 	};