- Document what iwx_rxmq_get_signal_strength() is doing in a comment, noting what the firmware returns and what math is being done on it to turn it into a dBm value.
- Document what iwx_get_noise() is supposed to do, that we can't just go do math with log numbers like we're doing, but also that we're seeing zeros in this firmware (AX210), which may mean we're decoding using the wrong structs.
- And handle the lowest noise floor value - it can't be -127dBm as that will throw things off. Cap it at -107dBm.
Note that this still isn't ENTIRELY correct, as in theory the RSSI
value in net80211 and wpa_supplicant should be relative to the
noise floor, not an absolute signal level. (eg ifconfig wlan0 list scan
will do (rssi/2)+noise for the 'S' signal part of S/N output, but
ifconfig wlan0 list sta will show the RSSI, (rssi/2)).