EDAC: Expose per-DIMM error counts in sysfs

EDAC: Expose per-DIMM error counts in sysfs

The old csrowX sysfs directories have per-csrow error counters, but the
new dimmX directories do not currently expose error counts.

EDAC already keeps these counts, add them to sysfs so per-DIMM counts
are still available when CONFIG_EDAC_LEGACY_SYSFS=n.

Signed-off-by: Aaron Miller <aaronmiller@fb.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20161103220153.3997328-1-aaronmiller@fb.com
Signed-off-by: Borislav Petkov <bp@suse.de>