build: sort and compact drivers and subsys CMakeLists and Kconfig

There are just list of child files to include, right now there's a hint
of that trying to be alphabetical but then entries have been added with
various logic, so one has to figure where stuff has to be added.

Rewrite these to:
- keep the list alphabetical, for CMakeLists unconditional first,
  conditional after so one just has to select and sort
- drop the spaces in the Kconfig
- use a single space between  target and directory
- rename from "Sub Systems" to "Subsystems" (single word)

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>