mce: acpi/apei: Add a boot option to disable ff mode for corrected errors

Add a boot option to disable firmware first mode for corrected errors.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Documentation/x86/x86_64/boot-options.txt

@@ -176,6 +176,11 @@ ACPI
 
   acpi=noirq	Don't route interrupts
 
+  acpi=nocmcff	Disable firmware first mode for corrected errors. This
+		disables parsing the HEST CMC error source to check if
+		firmware has set the FF flag. This may result in
+		duplicate corrected error reports.
+
 PCI
 
   pci=off		Don't use PCI