staging: don't recommend using lib80211

staging: don't recommend using lib80211

No longer document drivers should switch to lib80211,
they really should never have done that. While at it,
also remove the recommendation to use cfg80211, if it
switches to mac80211 then it implicitly uses cfg80211
but doesn't need to do anything about that, normally.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20241007202707.87481ddcfc00.I2cfb9940807e9c5017a052efcd3d1f2b6dc15fb1@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>