Add dlm user to usb and video groups

DisplayLinkManager daemon needs access to usb devices (usb group) and
DRM (video group). We want to run DisplayLinkManager as dlm user, thus
need for those two groups.

This change needs additional modification in freon overlay for lulu
board (as described in video file).

BUG=none
TEST=In built image in /etc/groups both usb and video groups
contain dlm user.
CQ-DEPEND=CL:328690

Change-Id: I085659bf283efb28ccb66c53e2ba986e6b3518fc
Signed-off-by: Dawid Kurek <dawid.kurek@displaylink.com>
Reviewed-on: https://chromium-review.googlesource.com/327630
Tested-by: Bernie Thompson <bhthompson@chromium.org>
Reviewed-by: Matthew Dempsky <mdempsky@chromium.org>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/profiles/base/accounts/group/usb b/profiles/base/accounts/group/usb
index a0dbffd..5075542 100644
--- a/profiles/base/accounts/group/usb
+++ b/profiles/base/accounts/group/usb
@@ -1,4 +1,5 @@
 group:usb
 gid:85
 # mtp for access to media on phones/tablets; brltty for braille.
-users:mtp,brltty
+# dlm for DisplayLinkManager daemon access to usb.
+users:mtp,brltty,dlm
diff --git a/profiles/base/accounts/group/video b/profiles/base/accounts/group/video
index 379316e..dcb9b47 100644
--- a/profiles/base/accounts/group/video
+++ b/profiles/base/accounts/group/video
@@ -2,4 +2,4 @@
 gid:27
 # Modifying users here might be overwritten by freon overlay.
 # You probably want to modify both here and freon.
-users:root,chronos,arc-camera,xorg
+users:root,chronos,arc-camera,xorg,dlm