accounts: Add drm_dp_aux group and related users+groups.

Added:
drm_dp_aux group - will give access to /dev/drm_dp_aux*
fwupdate-drm_dp_aux user+group - for firmware updaters that use drm_dp_aux devices
fwupdate-drm_dp_aux-i2c user+group - for firmware updaters that use drm_dp_aux and i2c devices

A pending firmware updater will use the fwupdate-drm_dp_aux-i2c user
for access to both /dev/drm_dp_aux* and /dev/i2c-* devices.

While the fwupdate-drm_dp_aux user will initially be unused,
its existence should encourage selecting a fwupdate-<something> user with
the minimal necessary permissions, should a new firmware updater be added
that needs access to /dev/drm_dp_aux* but not /dev/i2c-* .

BUG=b:112485400
TEST=Built OS image with new firmware updater run under
fwupdate-drm_dp_aux-i2c user, installed on DUT, flashed non-target firmware
on DUT, rebooted to trigger firmware update, the firmware update succeeded
using fwupdate-drm_dp_aux-i2c user.

Cq-Depend: chromium:2033704
Change-Id: If3c494e43fc2d861a87147f236c0ac46f3b49171
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/eclass-overlay/+/2033497
Tested-by: Matthew Blecker <matthewb@chromium.org>
Reviewed-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Bob Moragues <moragues@chromium.org>
Commit-Queue: Matthew Blecker <matthewb@chromium.org>
6 files changed
tree: 7fe0d2fc25cae6068fdb2d8552828aa3fae3c903
  1. eclass/
  2. metadata/
  3. profiles/
  4. OWNERS
  5. PRESUBMIT.cfg