[XL] Change in coreboot[master]: mb/lenovo: Add Thinkcentre M900 (Skylake/LGA 1151)

[Felix Singer (Code Review)]

Attention is currently required from: Alexander Couzens, Nicholas Chin, Paul Menzel.

Felix Singer has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74187?usp=email )

Change subject: mb/lenovo: Add Thinkcentre M900 (Skylake/LGA 1151)
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Patch Set 2:

(8 comments)

Patchset:

PS2: 
Only looked very quickly over it and found some nits.

File src/mainboard/lenovo/m900/Kconfig:

https://review.coreboot.org/c/coreboot/+/74187/comment/7f685ab4_2775415e :
PS2, Line 5: select BOARD_ROMSIZE_KB_16384
           : 	select HAVE_ACPI_RESUME
           : 	select HAVE_ACPI_TABLES
           : 	select HAVE_OPTION_TABLE
           : 	select HAVE_CMOS_DEFAULT
           : 	select INTEL_GMA_HAVE_VBT
           : 	select INTEL_INT15
           : 	select SOC_INTEL_SKYLAKE
           : 	select SKYLAKE_SOC_PCH_H
           : 	select SUPERIO_NUVOTON_COMMON_PRE_RAM
           : 	select MAINBOARD_HAS_LIBGFXINIT
```
select BOARD_ROMSIZE_KB_16384
select HAVE_ACPI_RESUME
select HAVE_ACPI_TABLES
select HAVE_CMOS_DEFAULT
select HAVE_OPTION_TABLE
select INTEL_GMA_HAVE_VBT
select INTEL_INT15
select MAINBOARD_HAS_LIBGFXINIT
select SKYLAKE_SOC_PCH_H
select SOC_INTEL_SKYLAKE
select SUPERIO_NUVOTON_COMMON_PRE_RAM
```

https://review.coreboot.org/c/coreboot/+/74187/comment/a1bd1ed6_c17fc8cd :
PS2, Line 27: 	hex
Remove

File src/mainboard/lenovo/m900/devicetree.cb:

https://review.coreboot.org/c/coreboot/+/74187/comment/1a49d6bb_6a6ba396 :
PS2, Line 21: 	r
Move that under iGPU

https://review.coreboot.org/c/coreboot/+/74187/comment/c26d4242_0b9029c2 :
PS2, Line 155: 			# Set LPC Serial IRQ mode
Seems superfluous too

https://review.coreboot.org/c/coreboot/+/74187/comment/47034b3b_9ddcb1cf :
PS2, Line 157: 
Remove superfluous lines

https://review.coreboot.org/c/coreboot/+/74187/comment/0cfa94ce_276f7705 :
PS2, Line 159: # LPC Interface
It's already in line 150

File src/mainboard/lenovo/m900/mainboard.c:

https://review.coreboot.org/c/coreboot/+/74187/comment/0bd34beb_b25e3700 :
PS2, Line 1: /* SPDX-License-Identifier: GPL-2.0-or-later */
Would you mind using that for the other files as well?