cpu/intel: Add CPU socket rPGA988B

Used by the Lenovo ThinkPad T520

Change-Id: I1009616cc4c18ebd0e3be7ceb50398617b49e3a3
Signed-off-by: Philipp Deppenwiese <zaolin@das-labor.org>
Reviewed-on: http://review.coreboot.org/5671
Reviewed-by: Idwer Vollering <vidwer@gmail.com>
Tested-by: build bot (Jenkins)
mainboard/lenovo: Add Lenovo Thinkpad T520 support

Short list of known issues for this patchset:

* Suspend/Resume - does not work
* Combi pci card for SD/MMC card reader with IEEE1394 - not found
* Shutdown - sometimes does not work as expected
* At least mysterious harddrive i/o

Change-Id: Iaba8d1f5e471cfeca20d82f4e1b416641e1f2ae9
Signed-off-by: Philipp Deppenwiese <zaolin@das-labor.org>
Reviewed-on: http://review.coreboot.org/5672
Tested-by: build bot (Jenkins)
Reviewed-by: Idwer Vollering <vidwer@gmail.com>