LinuxKPI: 802.11 scan update

Realtek's rtw88 is returning a hard-coded 1 in case they cannot
hw_scan (fw not advertising it). In that case if we want any scan
to run we need to fall-back to sw scan. Start dealing with this.
Long-term we probably need to keep internal state.

(cherry picked from commit d3ef7fb459ff924911e5276db0c04b13cd8074d9)