board: kevin: undefined i2c_xfer command
board: kevin: undefined i2c_xfer command

Save some space on kevin.

BUG=b:73205042
BRANCH=master
TEST=Can compile kevin with perform_calib addition.

Change-Id: If1526a90925ad20e4cc335e68de266cbc1ae6a42
Signed-off-by: Gwendal Grignou <190c5a5edfcf62e0246559bf31fa7548674de3ad@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/961223
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec