iwlwifi: mvm: enable MAC_FILTER_IN_BEACON when forced_assoc_off is set

Set the MAC_FILTER_IN_BEACON flag in iwl_mvm_mac_ctxt_cmd_sata() also
when forced_assoc_off is set, so it's aligned with when we are not
associated.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>