chipset_enable: Add support for C620-series Lewisburg PCH

This adds PCI IDs for C620-series PCHs and adds
CHIPSET_C620_SERIES_LEWISBURG as a new entry in the ich_chipset enum.

Lewisburg is very similar to Sunrise Point for Flashrom's purposes,
however one important difference is the way the "number of masters" is
interpreted from the flash descriptor (0-based vs. 1-based). There are
also new flash regions defined.

Change-Id: I96c89bc28bdfcd953229c17679f2c28f8b874d0b
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/20922
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
5 files changed