mac80211: don't call bss_info_changed on p2p-device/monitor

Since the idle decision rework, mac80211 started calling
bss_info_changed() for the driver's monitor interface,
which causes a crash for iwlwifi, but drivers generally
don't expect this to happen. Therefore, avoid it.

While at it, also prevent calling it in such cases and
only print a warning. For the P2P Device interface the
idle will no longer be called (no channel context), so
also prevent that and warn on it.

Reported-by: Chaitanya <chaitanya.mgit@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>