EDAC, skx, i10nm: Fix source ID register offset

The source ID register offset for Skylake server is 0xf0, while for
Icelake server is 0xf8. Pass the correct offset to get the source ID.

Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>