Add support for the 51nb X210

The 51nb X210 is a replacement motherboard for Thinkpad X200/X201 systems,
based on a modern Kabylake CPU. It also ships with no firmware protection,
making it an ideal Coreboot target. This port is based on the support for
the Skylake-based Purism Librem 13v3, with the following significant
changes:

* EC firmware is contained within the system SPI flash, and so a blob of
  EC firmware must be injected to a defined location during image build.
  A tool has been provided to do this.
* GPIO layout is different - this is currently just a raw import of the
  GPIO configuration from the vendor firmware
* The system has two DIMMs, so an additional SPD address has been added
* The USB port layout is different
* The EC must be enabled at boot time through SuperIO-style logical device
  configuration
* EC register layout is different, necessitating changes in the ACPI tables
* The HDA pins are different
* The genx_dec config is different

Signed-off-by: Matthew Garrett <mjg59@google.com>
Change-Id: If74621e76d703f629b54f1feb1acfc95cc72d183
---
M Makefile.inc
A configs/config.51nb_x210
M src/Kconfig
A src/ec/51nb/51nb.c
A src/ec/51nb/Kconfig
A src/ec/51nb/Makefile.inc
A src/ec/51nb/ec.h
A src/mainboard/51nb/Kconfig
A src/mainboard/51nb/Kconfig.name
A src/mainboard/51nb/x210/Kconfig
A src/mainboard/51nb/x210/Kconfig.name
A src/mainboard/51nb/x210/Makefile.inc
A src/mainboard/51nb/x210/acpi/ec.asl
A src/mainboard/51nb/x210/acpi/graphics.asl
A src/mainboard/51nb/x210/acpi/mainboard.asl
A src/mainboard/51nb/x210/acpi/platform.asl
A src/mainboard/51nb/x210/acpi/superio.asl
A src/mainboard/51nb/x210/acpi_tables.c
A src/mainboard/51nb/x210/board_info.txt
A src/mainboard/51nb/x210/devicetree.cb
A src/mainboard/51nb/x210/dsdt.asl
A src/mainboard/51nb/x210/gpio.h
A src/mainboard/51nb/x210/hda_verb.c
A src/mainboard/51nb/x210/hda_verb.h
A src/mainboard/51nb/x210/mainboard.c
A src/mainboard/51nb/x210/pei_data.c
A src/mainboard/51nb/x210/pei_data.h
A src/mainboard/51nb/x210/ramstage.c
A src/mainboard/51nb/x210/romstage.c
A util/51nb/51nb_ec_insert.c
A util/51nb/Makefile
31 files changed, 2,529 insertions(+), 1 deletion(-)