esp_hosted_ng: Fix some issues

esp_hosted_ng: Fix some issues

Fixed following issues as part of this change:
1. Fixed compilation issue due to incorrect logging function
2. cfg80211_sched_scan_stopped() needs rtnl lock for older kernels,
   removed its call from esp_stop()
3. Removed cfg and net stop calls from cmd teardown for modularity
4. cfg80211_unregister_wdev() is troublesome to cleanup in
   kernel < 5.10, used netdev cleanup functions in those.