[coreboot-gerrit] Change in coreboot[master]: mb/lenovo/{t420,t420s}: Convert to variant board

[Arthur Heymans (Code Review)]

Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40381 )

Change subject: mb/lenovo/{t420,t420s}: Convert to variant board
......................................................................

Patch Set 2:

Did you check if BUILD_TIMELESS=1 results in identical binaries for these boards?