This low level driver can find it useful to get the vif
when a remain on channel session is cancelled.

iwlwifi will need this soon.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Link: https://lore.kernel.org/r/20190723180001.5828-1-emmanuel.grumbach@intel.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>