build: fix nlohmann-json dependency

Previously the json dependency was only added when `json-control` or
`json-config` options were enabled, but there is now base code that
utilizes nlohmann-json directly (such as logger.hpp).  Add the
dependency at the top level.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia92e54f9bd4812af0977bcfa5479f093f7bdbc67
3 files changed