chipset_enable: Mark Intel HM75 as DEP

Tested reading and writing on a Samsung laptop (see CB:39388).

Change-Id: Idbb9c719a6f794a35293bb3b167cc1491d24d4fa
Signed-off-by: Evgeny Zinoviev <me@ch1p.io>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/39389


Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>