eclass-overlay/profiles: Remove 'chronos' user from 'iioservice' group

This commit removes the redundant 'chronos' user from 'iioservice'
group, as ARC++ gets access to the sysfs file with 'arc-sensor' group.
'chronos' user is not needed even in the transition stage.
The only user in 'iioservice' group should be 'iioservice' user.

BUG=chromium:1006141
TEST=None

Change-Id: I8d15574ce7b0bf2ae6ebf0a7c19bbecbbb4e9f89
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/eclass-overlay/+/2407992
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Cheng-Hao Yang <chenghaoyang@chromium.org>
Commit-Queue: Cheng-Hao Yang <chenghaoyang@chromium.org>
diff --git a/profiles/base/accounts/group/iioservice b/profiles/base/accounts/group/iioservice
index 4322649..7a48e09 100644
--- a/profiles/base/accounts/group/iioservice
+++ b/profiles/base/accounts/group/iioservice
@@ -1,3 +1,3 @@
 group:iioservice
 gid:20158
-users:chronos
+users:iioservice