amd64_edac: add module registration routines

Also, link into Kbuild by adding Kconfig and Makefile entries.

Borislav:
- Kconfig/Makefile splitting
- use zero-sized arrays for the sysfs attrs if not enabled
- rename sysfs attrs to more conform values
- shorten CONFIG_ names
- make multiple structure members assignment vertically aligned
- fix/cleanup comments
- fix function return value patterns
- fix err labels
- fix a memleak bug caught by Ingo
- remove the NUMA dependency and use num_k8_northbrides for initializing
  a driver instance per NB.
- do not copy the pvt contents into the mci struct in
  amd64_init_2nd_stage() and save it in the mci->pvt_info void ptr
  instead.
- cleanup debug calls
- simplify amd64_setup_pci_device()

Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>