mac80211_hwsim: add PMSR report support via virtio

PMSR (a.k.a. peer measurement) is generalized measurement between two
devices with Wi-Fi support. And currently FTM (a.k.a. fine time measurement
or flight time measurement) is the one and only measurement.

Add the necessary functionality to allow mac80211_hwsim to report PMSR
result. The result would come from the wmediumd, where other Wi-Fi
devices' information are kept. mac80211_hwsim only need to deliver the
result to the userspace.

In detail, add new mac80211_hwsim attributes HWSIM_CMD_REPORT_PMSR, and
HWSIM_ATTR_PMSR_RESULT. When mac80211_hwsim receives the PMSR result with
command HWSIM_CMD_REPORT_PMSR and detail with attribute
HWSIM_ATTR_PMSR_RESULT, received data is parsed to cfg80211_pmsr_result and
resent to the userspace by cfg80211_pmsr_report().

To help receive the details of PMSR result, hwsim_rate_info_attributes is
added to receive rate_info without complex bitrate calculation. (i.e. send
rate_info without adding inverse of nl80211_put_sta_rate()).

Signed-off-by: Jaewan Kim <jaewan@google.com>
Link: https://lore.kernel.org/r/20230322131637.2633968-6-jaewan@google.com
[fix uninitialized return value when there are no reports]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>