if_iwm - Update struct iwm_scan_results_notif. Remove old/unused definitions

if_iwm - Update struct iwm_scan_results_notif. Remove old/unused definitions

* Remove outdated notifications IWM_SCAN_ABORT_CMD,
  IWM_SCAN_START_NOTIFICATION and IWM_SCAN_RESULTS_NOTIFICATION.

* Remove unused enum iwm_scan_complete_status.

* Use the updated FW Api version 3 of struct iwm_scan_results_notif.

* No functional change, since struct iwm_scan_results_notif is never
  accessed in iwm at the moment.

Taken-From: Linux iwlwifi commits 1083fd7391e989be52022f0f338e9dadc048b063
            and 75118fdb63496e4611ab50380499ddd62b9de69f.