EDAC, amd64: Read MC registers on AMD Fam17h

Fam17h has a different set of registers and bitfields. Most of these
registers are read through SMN (System Management Network) rather
than PCI config space. Also, the derivation of various values is now
different.

Update amd64_edac to read the appropriate registers and extract the
correct values for Fam17h.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1479423463-8536-12-git-send-email-Yazen.Ghannam@amd.com


[ Save us the indentation level in read_mc_regs(), add defines ]
Signed-off-by: Borislav Petkov <bp@suse.de>