This will be used with the upcoming entry.S changes to signal
that there's a machine check pending that cannot be handled in
the Machine check handler itself.
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NSven Schnelle <svens@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>