Add EDAC support for ecc errors reporting on the synopsys ddr
controller. The ddr ecc controller corrects single bit errors and
detects double bit errors.

Selected important-ish notes from the changelog:

- I have not taken care of spliting synps_edac_geterror_info function as
it adds additional indentation levels and moreover the existing changes
were made as part of the v2 review comments

- Removed dt binding info as already there is a binding info available
under memorycontroller. so, updated ecc info there.

- Shortened the prefix "sysnopsys" to "synps"
Signed-off-by: NPunnaiah Choudary Kalluri <punnaia@xilinx.com>
Link: http://lkml.kernel.org/r/a728a8d4678f4dbf9de189a480297c3d@BY2FFO11FD034.protection.gbl
[ Boris: massage commit message. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>