x86/mce: Add quirk for instruction recovery on Sandy Bridge processors

Sandy Bridge processors follow the SDM (Vol 3B, Table 15-20) and
set both the RIPV and EIPV bits in the MCG_STATUS register to
zero for machine checks during instruction fetch. This is more
than a little counter-intuitive and means that Linux cannot
recover from these errors. Rather than insert special case code
at several places in mce.c and mce-severity.c, we pretend the
EIPV bit was set for just this case early in processing the
machine check.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/180a06f3f357cf9f78259ae443a082b14a29535b.1343078495.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>