Change in coreboot[master]: drivers/intel/i210: Set log level to BIOS_NOTICE on missing MAC address

[Paul Menzel (Code Review)]

Attention is currently required from: Werner Zeh, Patrick Rudolph.
Paul Menzel has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62008 )

Change subject: drivers/intel/i210: Set log level to BIOS_NOTICE on missing MAC address
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Patch Set 1:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/62008/comment/dd9e1efb_1b3e352f 
PS1, Line 12:
> I do not see why the MAC address should be runtime configurable. […]

It would be nice to have more detailed error handling then, as a MAC address is still good to have for the OS on a device with a network card. Maybe add error/warnings message to the corresponding paths in `mainboard_get_mac_address()`.

1.  Notice if no `hwinfo.hex` is present, saying that one should be deployed for proper network card operation.
2.  Show an error if the MAC address is invalid.