iwlwifi: mvm: wait for TE notif when protecting TDLS session

Make sure that when running the TDLS discovery session
protection - the time event that ensures we remain on channel
has been scheduled and started running before leaving.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>