Update to support raviole-device as an external module

* Move build objects to Kbuild files (from Makefile)
* Include the Makefile.include from gs/kernel/device-modules. This
  makefile updates EXTRA_CFLAGS and EXTRA_SYMBOLS to be able to include
  headers from the device-modules project as well as link against modules
  under the device-modules project.
* Reformat the Makefile and Kbuilds to use tabs appropriately
* Update BUILD.bazel to support these changes as well.

Signed-off-by: Will McVicker <willmcvicker@google.com>
Change-Id: Iab7408dc87813fdd6fe4d059033b289c52d8f830