chipset_enable: Cleanup the SiS handlers into common

We don't use this chipset on Chromebooks so this should matter
apart from reducing the diff with upstream.

BUG=chromium:478356
BRANCH=none
TEST=still builds

Change-Id: I2b7302a38bb2e9bb4dd81d8756973c05d6b659c1
Signed-off-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/1757761
Reviewed-by: Sam McNally <sammc@chromium.org>
1 file changed