Allow mce to reset instead of panic on UE

Allow mce to reset instead of panic on UE

The intent of this patch is to ensure that the mce stack is not
put in the panic stack trace when the kernel reboots due to the
Uncorrectable Error. The mce stack in the panic trace confuses
the administrator and falsely implicates mce module as a culprit.
Hence a synchronization flag is added to machine restart the system
when it experience uncorrectable error.

Orabug: 24745271

Signed-off-by: Ashok Vairavan <ashok.vairavan@oracle.com>
Reviewed-by: Dan Duval <dan.duval@oracle.com>