Add EDAC support for Altera SoC SDRAM Controller

[tthayer at altera.com]

[PATCHv5 1/3] dts: socfpga: Add bindings for Altera SoC SDRAM
[PATCHv5 2/3] dts: socfpga: Add bindings for Altera SoC SDRAM EDAC
[PATCHv5 3/3] edac: altera: Add EDAC support for Altera SoC SDRAM