Add ip-peripheral group/user

BUG=b:133250323
TEST=Checked for collisions with display-accts.py --lint, built and deployed the ip-peripheral and manually verified it worked

Change-Id: I8acd5675a06eb821bcfe48d1da6e304ba2a9458d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/eclass-overlay/+/1671994
Tested-by: Pablo Ceballos <pceballos@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Commit-Queue: Pablo Ceballos <pceballos@chromium.org>
Auto-Submit: Pablo Ceballos <pceballos@chromium.org>