[L] Change in coreboot[main]: mainboard: Add MSI MS-7788

[Angel Pons (Code Review)]

Attention is currently required from: Felix Singer, Maximilian Brune, Name of user not set #1005283.

Angel Pons has posted comments on this change by Name of user not set #1005283. ( https://review.coreboot.org/c/coreboot/+/79979?usp=email )

Change subject: mainboard: Add MSI MS-7788
......................................................................

Patch Set 9:

(4 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/79979/comment/9dcd282d_9ed974bc?usp... :
PS9, Line 24: * I had changed Sandybridge `chipset.cb` because I
            :   was getting warnings in my logs about leftover
            :   static devices
            :   * Is there something wrong with my configuration
            :     or are those warnings supposed to be there?
            :   * Do I leave the warnings be?
            :   * Or is there something else I can do?
There should be no need to modify chipset.cb

File src/mainboard/msi/ms7788/dsdt.asl:

https://review.coreboot.org/c/coreboot/+/79979/comment/cbd6c55f_b5ff5dc9?usp... :
PS9, Line 11: /* OEM revision */
I'm pretty sure that's the number hardcoded in autoport. Please remove the comment

```suggestion
    0x20141018
```

File src/mainboard/msi/ms7788/gma-mainboard.ads:

PS9: 
Please use 3 spaces for indentation (it's the convention for Ada source code in coreboot)

File src/northbridge/intel/sandybridge/romstage.c:

https://review.coreboot.org/c/coreboot/+/79979/comment/55fbf13b_3ed7fb5d?usp... :
PS9, Line 56: 	//if (mchbar_read16(SSKPD_HI) == 0xcafe)
> Please avoid modifying common code. […]

I think one of the Dell Optiplex boards needs a similar workaround for some reason. It's implemented in mainboard code.