wifi: mac80211: remove SMPS from AP debugfs

The spatial multiplexing power save feature does not apply to
AP mode. Remove it from debugfs in this case.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230301115906.01b167027dd5.Iee69f2e4df98581f259ef2c76309b940b20174be@changeid


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