LinuxKPI: 802.11: setup a default link[0] and adjust related needs

Setup more link_conf/deflink fields for vif/sta as are needed to allow
us to work with the KPI bits in a non-MLO configuration.
In lkpi_sta_scan_to_auth() set the bss_conf values before calling into
the driver for chanctx setup/updates as certain values (e.g., beacon_int)
need to be set before; we still call the MO function for the updates
after to keep the expected workflow.
Deal with the (to be dealt with otherwise later) net80211 ni swaps and
update the addresses on the deflink as well as otherwise firmware will
hit asserts or things will not work (e.g. indicating the peer is us).

Sponsored by: The FreeBSD Foundation
MFC after: 3 days