BACKPORT: mac80211-hwsim: add missing policy entries

A few recent additions to the netlink attributes neglected
to add policy entries, fix that now.

Reported-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
(cherry picked from commit de29eda8)
[astrachan: Omit policy for HWSIM_ATTR_FREQ, which has not been
            backported]
Bug: 70214720
Change-Id: Ica4da06e03bcfbf954399ba05a88e5552d60feb9
Signed-off-by: Alistair Strachan <astrachan@google.com>