mcelog: Identify Ivy Bridge properly

Uniquely identify Ivy Bridge even though the machine checks are the same
for Sandy Bridge and Ivy Bridge.  This makes the output for the processor
display "Ivy Bridge".

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: tony.luck@intel.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Merge branch 'master' of ssh://github.com/andikleen/mcelog