wifi: mac80211_hwsim: refactor NAN timer handling

wifi: mac80211_hwsim: refactor NAN timer handling

Refactor the NAN timer to more closely track the where in the NAN
schedule the device currently is. Do this by having an hrtimer that
fires at the start of every slot.

For now continue to update the current channel at the start of the DW.
In the future, the correct channel according to the schedule should be
used everywhere.

This is in preparation to more accurately simulate more of the NAN
logic.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260504101829.feb8e02b234e.I46da3cabea8624ba2e6c91bd2afecd2dc6553c5a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>