wifi: mac80211: support initialising an S1G short beaconing BSS

Introduce the ability to parse the short beacon data and long
beacon period. The long beacon period represents the number of beacon
intervals between each long beacon transmission. Additionally,
as a BSS cannot change its configuration such that short beaconing
is dynamically disabled/enabled without tearing down the interface
- we ensure we have an existing short beacon before performing
the update.

Signed-off-by: Lachlan Hodges <lachlan.hodges@morsemicro.com>
Link: https://patch.msgid.link/20250717074205.312577-3-lachlan.hodges@morsemicro.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>