wifi: cfg80211: add support for link id attribute in NL80211_CMD_DEL_STATION

wifi: cfg80211: add support for link id attribute in NL80211_CMD_DEL_STATION

Currently whenever NL80211_CMD_DEL_STATION command is called without any
MAC address, all stations present on that interface are flushed.
However with MLO there is a need to flush such stations only which are
using at least a particular link from the AP MLD interface.

For example - 2 GHz and 5 GHz are part of an AP MLD.
To this interface, following stations are connected -
   1. One non-EHT STA on 2 GHz link.
   2. One non-EHT STA on 5 GHz link.
   3. One Multi-Link STA having 2 GHz and 5 GHz as active links.

Now if currently, NL80211_CMD_DEL_STATION is issued by the 2 GHz link
without any MAC address, it would flush all station entries. However,
flushing of station entry #2 at least is not desireable since it
is connected to 5 GHz link alone.

Hence, add an option to pass link ID as well in the command so that if link
ID is passed, stations using that passed link ID alone would be flushed
and others will not.

So after this, station entries #1 and #3 alone would be flushed and #2 will
remain as it is.

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Link: https://msgid.link/20240205162952.1697646-2-quic_adisi@quicinc.com
[clarify documentation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>