mediatek: Move mtcmos code to a common directory

Move mtcmos code which can be reused into a common directory under
soc/mediatek.

BUG=b:80501386
BRANCH=none
TEST=Boots correctly on Elm

Change-Id: I92b138890424b4f4a68cdb00bf2326eef9cd87b7
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/27029
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
3 files changed