wifi: mac80211: handle non-MLO mode as well in ieee80211_num_beaconing_links()

wifi: mac80211: handle non-MLO mode as well in ieee80211_num_beaconing_links()

Currently, ieee80211_num_beaconing_links() returns 0 when the interface
operates in non-ML mode. However, non-MLO mode is equivalent to having a
single link. Therefore, the function can handle the non-MLO case as well.
This adjustment will also eliminate the need for deflink usage in certain
scenarios.

Hence, implement changes to handle the non-MLO case as well. There is
no change in functionality, and no existing user-visible bug is getting
fixed. This update simply makes the function generic to handle all cases.

Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/linux-wireless/16499ad8e4b060ee04c8a8b3615fe8952aa7b07b.camel@sipsolutions.net/
Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Link: https://patch.msgid.link/20250515-fix_num_beaconing_links-v1-1-4a39e2704314@oss.qualcomm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>