iwlwifi: mvm: remove duplicated fields in mvm reorder buffer

The reason station id and tid fields are both in baid data and
in the reorder buffer per queue is that we couldn't access the
baid_data in the reorder timer functions.
Now that we do some pointer math and access it anyway, those
fields can be removed.
This save some space and some code.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>