stoneyridge: Rename hudson to southbridge

Simplify funciton names and remove reference to hudson in stoneyridge.
The southbridge in Stoney Ridge is Kern and hudson naming is
no longer accurate.

BUG=b:62200157
BRANCH=none
TEST=Build and booted on Kahlee.

Change-Id: Ide7a72dae69b881997101f1e37a1ac739901744d
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/20912
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
34 files changed