Add EDAC support for Altera SDRAM Controller

[tthayer at altera.com]

[PATCHv6 1/3] dt: bindings: Addition of the Altera SDRAM controller
[PATCHv6 2/3] dt: bindings: Addition of the Altera SDRAM EDAC 
[PATCHv6 3/3] edac: altera: Add EDAC support for Altera SoC SDRAM