EDAC, pnd2_edac: Add new EDAC driver for Intel SoC platforms

EDAC, pnd2_edac: Add new EDAC driver for Intel SoC platforms

Initial target for this driver is the Intel Apollo Lake platform and
Denverton micro-server, they use the same internal memory controller IP
called Pondicherry2.

Memory controller registers are not in PCI config space like earlier
Intel memory controllers. For Apollo Lake platform they are accessed via
a "side-band" interface, for Denverton micro-server they are access via
PCI config space and memory map I/O. This driver is for Apollo Lake and
Denverton, but only the Denverton is fully enabled while we wait for the
sideband driver.

Apollo lake driver and initial cut at Denverton driver by Tony Luck.
Extensive cleanup, refactoring and basic verification by Qiuxu Zhuo.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170308174539.14432-1-qiuxu.zhuo@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>