mac80211_hwsim: Add debugfs to control rx status RSSI

Set the base RSSI of a TX frame. The final RSSI of the frame will be
the base RSSI + the radio's TX power

Signed-off-by: Beni Lev <beni.lev@intel.com>
Link: https://lore.kernel.org/r/20220210201649.dddebbb55a7f.I6c0607694587b577070339078829fcc20dfcfe2c@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>