Delete config.dtb support

With Fizz/Coral migrations complete, this deletes legacy support for
device-tree based cros_config impls.

BUG=b:119104647
TEST=cros tryjob coral-release-trybot
CQ-DEPEND=CL:*709755, CL:*709786

Change-Id: I8b0b347a9e6b9a8fb4397945d558de1c0fc9aea9
Reviewed-on: https://chromium-review.googlesource.com/1319952
Commit-Ready: C Shapiro <shapiroc@chromium.org>
Tested-by: C Shapiro <shapiroc@chromium.org>
Reviewed-by: Alex Klein <saklein@chromium.org>
1 file changed