EDAC, amd64: Move global code out of instance functions

EDAC, amd64: Move global code out of instance functions

We have a few functions that register/unregister an ECC error decoding
routine. These functions are called when we init/remove instances.
However, they are global and so don't need to be registered/unregistered
multiple times.

So move them out of the init/remove instance functions and into the
module init/exit routines.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1485297149-13733-4-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>