EDAC, amd64: Add x86cpuid sanity check during init

EDAC, amd64: Add x86cpuid sanity check during init

Match one of the devices in amd64_cpuids[] before loading the module.
This is an additional sanity check against users trying to load
amd64_edac_mod on unsupported systems.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1485537863-2707-9-git-send-email-Yazen.Ghannam@amd.com
[ Get rid of err_ret label, make it a bit more readable this way. ]
Signed-off-by: Borislav Petkov <bp@suse.de>