RAS/CEC: Reduce offline page threshold for Intel systems

A large scale study of memory errors on Intel systems in data centers
showed that aggressively taking pages with corrected errors offline is
the best strategy of using corrected errors as a predictor of future
uncorrected errors.

Set the threshold to "2" on Intel systems. AMD guidance is that this is
not necessary for their systems.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: https://lore.kernel.org/r/20220607212015.175591-1-tony.luck@intel.com
Link: https://lore.kernel.org/r/YulOZ/Eso0bwUcC4@agluck-desk3.sc.intel.com