amd64_edac: simple fix to allow reporting of CECC errors

This allows the errors to be further decoded and mapped to csrows.
Tested with ECC debug dimms and an Rev F cpu based system.

Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>