iwlwifi: mvm: free dqa queues on STA removal also in non-bss

Support queue removal in DQA mode in iwl_mvm_rm_sta() also when
the device isn't a STA connected to an AP.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>