mb/google/octopus: Use the newly added override devicetree feature

Now that sconfig is able to support variant-specific override trees,
this change updates octopus boards to use this feature. Following
devices are moved from baseboard devicetree to variant specific
1. Touchscreen
2. Trackpad
3. Digitizer
4. Audio codec

TEST=Verified that the right devices show up in static.c for each

Change-Id: I8df0cdf4dbcd7613aa4ef4042c272eca2915da9e
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/27219
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
7 files changed