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• Remove outdated notifications IWM_SCAN_ABORT_CMD,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.

Submitted by: Augustin Cavalier <waddlesplash@gmail.com> (Haiku)
Obtained from: DragonFlyBSD (c947b0b8dc96dabefd63f7b70d53695e36c7b64f)