Change in coreboot[master]: mb/ocp/deltalake: Update SMBIOS type 0 firmware version by VPD variable

[insomniac (Code Review)]

insomniac has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41720 )

Change subject: mb/ocp/deltalake: Update SMBIOS type 0 firmware version by VPD variable
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Patch Set 11:

(1 comment)

https://review.coreboot.org/c/coreboot/+/41720/11/src/mainboard/ocp/deltalak... 
File src/mainboard/ocp/deltalake/ramstage.c:

https://review.coreboot.org/c/coreboot/+/41720/11/src/mainboard/ocp/deltalak... 
PS11, Line 79: const char *smbios_mainboard_bios_version(void)
this feature would be useful beyond just DeltaLake. I am wondering whether we can generalize it in a way that:
* doesn't change coreboot's default behaviour
* allows more granular control (e.g. what is the fallback if the VPD variable is missing?)

Some ideas to do that:
1. make this a global Kconfig tunable (e.g. CONFIG_VERSION_VPD, or any better name), whose value is the name of the VPD variable to read (instead of the hard-coded "version")
2. if this is set, override the default behaviour, otherwise use the normal versioning system
3. add a dependent config value for default value if the VPD var is missing (e.g. CONFIG_VERSION_VPD_DEFAULT_IF_MISSING), whose value would be used if VPD version is missing; and if not set, will return `coreboot_version`