mac80211_hwsim: fixes kernel crash during mac80211_hwsim init

Creating radios during startup follows a different code path than
HWSIM_CMD_NEW_RADIO. The problem was that param.iftypes was not
being set to the deafult before calling mac80211_hwsim_new_radio

Signed-off-by: James Prestwood <james.prestwood@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>