mainboard: Add Synology DS918+

I'm new to coreboot.
This port is based on 4.13, this board boots. Tested with tianocore.
Can provide serial logs, original Synology's DSM OS works fine with this
port. Can run tests on my board.
Now works on Master.
Things todo:
* polish
* I211 ethernet chips initialise with 00:11:22:33:44:55 MAC's as in
  vendor's, is there a better way?
* Sata 88SE9215 is gpio controlled, 4 chips, 1 for each sata port. All
  sata is turned off by default, is there a better way?
* 2nd HSUART Serial doesn't work in OS, only in original DSM. Tried all
  console=ttyS*,115200 and all 'set tty com*' (as per obsd), probably
  not cb problem.
* Freebsd usb stick causes X86 exception, OpenBSD fails to boot at
  entry point 0x1001000. Both have apl support. log:
  https://clbin.com/JrurJ
* ...

Patch set 2
Reformated gpio part and dsdt.

Here are serial logs:
https://clbin.com/tHOE7 -- Master branch
https://clbin.com/wp4R8 -- 4.13 + seabios, same code except 1 include in
dsdt
https://clbin.com/iUrgJ -- 4.13 + tianocore, same code...

Video test:
https://schizoden.xyz/videos/watch/816c5a68-af6f-4dd4-8c7e-43d068410822

Patch set 3/4
More gpio reformating, added data.vbt from vendors bios.
* trim spare lines on the end, for jenkins sake

Patch set 5/6
Removed data.vbt, causes serial to shut off at post 0x98
Fixed cbfs>mem-mapped area from ifwi + MCACHE -400 err -- .fmd
Added cmos.layout cmos.default
Edited pci-e devices and turned on vtd in devicetree.cb
* forgot to remove dptf, which was added as a test.

Patch set 7

Fixed ethernet by removing register pcie_rp_clkreq_pin from devicetree
Was able to finally replace vendor's bios in my daily NAS's duties

Change-Id: Ib837e0819c97a617e5558480e7cdac05e3cff185
Signed-off-by: mkjOoB <dump@schizoden.xyz>
---
A src/mainboard/synology/Kconfig
A src/mainboard/synology/Kconfig.name
A src/mainboard/synology/ds918plus/Kconfig
A src/mainboard/synology/ds918plus/Kconfig.name
A src/mainboard/synology/ds918plus/Makefile.inc
A src/mainboard/synology/ds918plus/board_info.txt
A src/mainboard/synology/ds918plus/bootblock.c
A src/mainboard/synology/ds918plus/cmos.default
A src/mainboard/synology/ds918plus/cmos.layout
A src/mainboard/synology/ds918plus/devicetree.cb
A src/mainboard/synology/ds918plus/ds918plus.fmd
A src/mainboard/synology/ds918plus/dsdt.asl
A src/mainboard/synology/ds918plus/early_gpio.c
A src/mainboard/synology/ds918plus/gpio.c
A src/mainboard/synology/ds918plus/gpio.h
A src/mainboard/synology/ds918plus/mainboard.c
A src/mainboard/synology/ds918plus/romstage.c
17 files changed, 633 insertions(+), 0 deletions(-)