docs: remove no-access privilege role

The priv-noaccess role has been removed from OpenBMC.

Ref: https://gerrit.openbmc.org/q/topic:%22remove-priv-noaccess%22

Change-Id: Id47cefd747c6482a9c9a6413f9338c27adc52a4f
Signed-off-by: Vijaysankar Ravi <vijaysankarr@ami.com>